diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index 2c315bda..02f7d19d 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -304,7 +304,7 @@ flowchart TD
 
 `Process.ProcessFile()` runs one file through the steps below, in this order. The node ids `P01` onward follow the order of the step calls in `Process.ProcessFile()`, and `ArchitectureDiagramTests` fails when they differ.
 
-A step that returns false leaves the chain at the abort node, except `DeleteNonMkvFile()`, whose false return ends the file as a success. From `RemuxByExtension()` on, a cancel seen after a step does the same. `DeleteNonMkvFile()`, `IsSidecarWriteable()`, `MakeExtensionLowercase()` and `VerifyMediaInfo()` have no cancel check after them. A step that throws while no cancel is requested also leaves the chain at the abort node.
+A step that returns false leaves the chain at the abort node, except `DeleteMismatchedSidecarFile()` and `DeleteNonMkvFile()`, whose false return ends the file as a success. From `RemuxByExtension()` on, a cancel seen after a step does the same. `DeleteNonMkvFile()`, `IsSidecarWriteable()`, `MakeExtensionLowercase()` and `VerifyMediaInfo()` have no cancel check after them. A step that throws while no cancel is requested also leaves the chain at the abort node.
 
 ```mermaid
 flowchart TD
@@ -315,7 +315,7 @@ flowchart TD
   G3 --> P01["IsWriteable()"]
   P01 -->|"read-only, skipped"| AB
   P01 --> P02["DeleteMismatchedSidecarFile()"]
-  P02 -->|"orphan sidecar deleted, S3"| AB
+  P02 -->|"orphan sidecar deleted"| SKP
   P02 --> G4{"SidecarFile.IsSidecarFile()"}
   G4 -->|yes| IGN
   G4 -->|no| P03["RemuxByExtension(): ReMux, ReMuxExtensions"]
@@ -371,8 +371,6 @@ flowchart TD
   G5 -->|yes| RET(["Result false, return the state and final path"])
   G5 -->|no| DF["DeleteFailedFile(): DeleteInvalidFiles deletes the media file, and the sidecar of an MKV file, unless cancelled, a tool run for the file failed to launch, threw, or was killed by a signal outside Windows, or the state has PostDecodeTimestamps"]
   DF --> RET
-  classDef suspect stroke:#c00,stroke-width:2px,stroke-dasharray:5 3
-  class P02 suspect
 ```
 
 `ProcessDriver.ProcessFiles()` counts the tool runs of each file that fail to launch, are cancelled, or throw, since such a run leaves the media unjudged. Outside Windows, it counts a tool run a signal terminates the same way, since that run ended before a result. It counts an FfMpeg verify run a signal terminates apart, since an external kill and a crash on corrupt media exit alike. `DeleteFailedFile()` does not delete a file that had any such tool run. It also keeps a file whose state carries `PostDecodeTimestamps`. A delete that throws is logged, and the file counts as not deleted.
@@ -748,7 +746,6 @@ The table lists the `StatesType` flags each step sets, and the flags it clears.
 
 Each entry describes a branch the diagrams mark, as the code behaves today, and links the issue that tracks its fix. Update the diagram and remove the entry when the fix lands.
 
-- **S3** ([#1070](https://github.com/ptr727/PlexCleaner/issues/1070)): Deleting an orphan sidecar returns false, so the file counts as an error and runs `DeleteFailedFile()`. Deleting a non-MKV file in `DeleteNonMkvFile()` counts as a success.
 - **S6** ([#1073](https://github.com/ptr727/PlexCleaner/issues/1073)): `Convert.ReMuxToMkv()` moves its output to the `.mkv` name with overwrite, so `name.avi` replaces an existing `name.mkv`. `MakeExtensionLowercase()` replaces a lowercase sibling on a case-sensitive filesystem the same way.
 - **S7** ([#1074](https://github.com/ptr727/PlexCleaner/issues/1074)): `RepairMetadataErrors()` can pass with errors left. `RepairMetadataRemux()` does nothing with `ReMux` off, and `RepairMetadataFlags()` neither re-checks its result nor marks `VerifyFailed`.
 - **S9** ([#1076](https://github.com/ptr727/PlexCleaner/issues/1076)): `ReEncode()` and `DeInterlace()` only warn when their flag is already set. `ReEncode()` processes output that still matches its selection again on every run. `DeInterlace()` does the same while a tool still flags the video as interlaced, since its idet scan skips a file already `DeInterlaced`.
diff --git a/HISTORY.md b/HISTORY.md
index 168dc9a6..cc883e51 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -70,6 +70,8 @@ Utility to optimize media files for Direct Play in Plex, Emby, Jellyfin, etc.
     - The repeated steps are cover art, tags, metadata, Matroska structure, closed captions, track language, duplicate tracks and default flags.
     - A rewrite by FfMpeg or HandBrake, such as a deinterlace, re-encode or repair, can undo their work.
     - Before, it repeated only the metadata, unknown language, tag and default flag steps.
+  - Deleting a sidecar file with no matching MKV file counts as a successful cleanup, as deleting a non-MKV file does.
+    - Before, it counted as an error and reported the deletion step as the failed step.
 - Version 3.22:
   - Added always-on runtime metrics published via `System.Diagnostics.Metrics` under the `PlexCleaner.Process` meter, readable with `dotnet-counters` with no extra infrastructure.
     - Overall progress is operation-weighted: each heavy full-file operation (the closed-caption and interlace scans, bitrate analysis, re-encode, deinterlace, and verify) counts the file's size as work to do when it starts and as work done when it finishes, so a run mixing tiny and huge files reports the actual work completed, and the total grows as the non-deterministic per-file path is discovered.
diff --git a/PlexCleaner/Process.cs b/PlexCleaner/Process.cs
index 0cd8ddf3..55515e7d 100644
--- a/PlexCleaner/Process.cs
+++ b/PlexCleaner/Process.cs
@@ -89,8 +89,7 @@ out string? failedOperation
                 operation = nameof(processFile.DeleteMismatchedSidecarFile);
                 if (!processFile.DeleteMismatchedSidecarFile(ref modified))
                 {
-                    // Error
-                    result = false;
+                    result = true;
                     break;
                 }
 
diff --git a/PlexCleanerTests/OrphanSidecarTests.cs b/PlexCleanerTests/OrphanSidecarTests.cs
new file mode 100644
index 00000000..d591c26c
--- /dev/null
+++ b/PlexCleanerTests/OrphanSidecarTests.cs
@@ -0,0 +1,57 @@
+using AwesomeAssertions;
+using PlexCleaner;
+using Xunit;
+
+namespace PlexCleanerTests;
+
+[Collection("Sequential")]
+public sealed class OrphanSidecarTests : IDisposable
+{
+    private readonly string _directory = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
+
+    public OrphanSidecarTests() => _ = Directory.CreateDirectory(_directory);
+
+    public void Dispose() => Directory.Delete(_directory, true);
+
+    [Fact]
+    public void ProcessFile_OrphanSidecar_DeletesAndSucceeds()
+    {
+        string sidecarFile = SidecarFile.GetSidecarName(Path.Combine(_directory, "name.mkv"));
+        File.WriteAllText(sidecarFile, "");
+
+        _ = Process
+            .ProcessFile(
+                sidecarFile,
+                out bool modified,
+                out bool ignored,
+                out SidecarFile.StatesType state,
+                out _,
+                out string? failedOperation
+            )
+            .Should()
+            .BeTrue();
+
+        _ = File.Exists(sidecarFile).Should().BeFalse();
+        _ = modified.Should().BeTrue();
+        _ = ignored.Should().BeFalse();
+        _ = state.Should().HaveFlag(SidecarFile.StatesType.FileDeleted);
+        _ = failedOperation.Should().BeNull();
+    }
+
+    [Fact]
+    public void ProcessFile_SidecarWithMkv_IgnoresAndKeeps()
+    {
+        string mediaFile = Path.Combine(_directory, "name.mkv");
+        string sidecarFile = SidecarFile.GetSidecarName(mediaFile);
+        File.WriteAllText(mediaFile, "");
+        File.WriteAllText(sidecarFile, "");
+
+        _ = Process
+            .ProcessFile(sidecarFile, out _, out bool ignored, out _, out _, out _)
+            .Should()
+            .BeTrue();
+
+        _ = ignored.Should().BeTrue();
+        _ = File.Exists(sidecarFile).Should().BeTrue();
+    }
+}