diff --git a/src/BizHawk.Client.EmuHawk/tools/TAStudio/TAStudio.ListView.cs b/src/BizHawk.Client.EmuHawk/tools/TAStudio/TAStudio.ListView.cs
index 6d09877b733..e6ed61dcf94 100644
--- a/src/BizHawk.Client.EmuHawk/tools/TAStudio/TAStudio.ListView.cs
+++ b/src/BizHawk.Client.EmuHawk/tools/TAStudio/TAStudio.ListView.cs
@@ -370,6 +370,45 @@ private bool TasView_QueryFrameLag(int index, bool hideWasLag)
 			return (lag.Lagged.HasValue && lag.Lagged.Value) || (hideWasLag && lag.WasLagged.HasValue && lag.WasLagged.Value);
 		}
 
+		/// <param name="selection">
+		/// list of row indices sorted ascending, as returned by <c>TasView.SelectedRows</c>,
+		/// and must not be empty (so there must be a selection)
+		/// </param>
+		/// <remarks>fills with <see langword="false"/> (unheld) if held on all selected frames, <see langword="true"/> (held) otherwise</remarks>
+		private void ToggleButtonStateOnFrames(int[] selection, string buttonName)
+		{
+			// nifty taseditor logic
+			// your TAS Editor logic failed us (it didn't account for non-contiguous `SelectedRows`) --yoshi
+			var allPressed = selection.All(index => CurrentTasMovie.BoolIsPressed(index, buttonName))
+				&& selection[selection.Length - 1] != CurrentTasMovie.FrameCount; // last movie frame can't have input, but can be selected
+			var iSelection = 0;
+			var lastFrameIndexSeen = selection[iSelection] - 1;
+			while (iSelection < selection.Length)
+			{
+				var index = selection[iSelection];
+				if (index - lastFrameIndexSeen is not 1) break;
+				lastFrameIndexSeen = index;
+				iSelection++;
+			}
+			// `iSelection` now points to the element after the last of the first contiguous block--if the whole selection is contiguous, it's pointing after the end of the array...
+			CurrentTasMovie.SetBoolStates(frame: selection[0], count: iSelection, buttonName, val: !allPressed);
+			var blockStart = iSelection;
+			lastFrameIndexSeen = selection[iSelection] - 1;
+			while (iSelection < selection.Length) // ...and these will be equal, so the loop will end immediately
+			{
+				var index = selection[iSelection];
+				if (index - lastFrameIndexSeen is not 1)
+				{
+					// discontinuity; split off another block, and this is now the start of the next block
+					CurrentTasMovie.SetBoolStates(frame: selection[blockStart], count: iSelection - blockStart, buttonName, val: !allPressed);
+					blockStart = iSelection;
+				}
+				lastFrameIndexSeen = index;
+				iSelection++;
+			}
+			CurrentTasMovie.SetBoolStates(frame: selection[blockStart], count: iSelection - blockStart, buttonName, val: !allPressed); // `count` arg will be 0 if the whole selection is contiguous
+		}
+
 		private void TasView_ColumnClick(object sender, InputRoll.ColumnClickEventArgs e)
 		{
 			if (TasView.AnyRowsSelected)
@@ -382,25 +421,13 @@ private void TasView_ColumnClick(object sender, InputRoll.ColumnClickEventArgs e
 				}
 				else if (columnName != CursorColumnName)
 				{
-					var frame = TasView.AnyRowsSelected ? TasView.FirstSelectedRowIndex : 0;
 					var buttonName = TasView.CurrentCell.Column!.Name;
 
 					if (ControllerType.BoolButtons.Contains(buttonName))
 					{
 						if (ModifierKeys != Keys.Alt)
 						{
-							// nifty taseditor logic
-							bool allPressed = true;
-							foreach (var index in TasView.SelectedRows)
-							{
-								if (index == CurrentTasMovie.FrameCount // last movie frame can't have input, but can be selected
-									|| !CurrentTasMovie.BoolIsPressed(index, buttonName))
-								{
-									allPressed = false;
-									break;
-								}
-							}
-							CurrentTasMovie.SetBoolStates(frame, TasView.SelectedRows.Count(), buttonName, !allPressed);
+							ToggleButtonStateOnFrames(TasView.SelectedRows.ToArray(), buttonName);
 						}
 						else
 						{