Apple Final Cut Pro 7 - Manual (Page 614)

The resulting edit looks like this:
The audio precedes the video and begins at the sequence In point.
Example: Split Edit in the Viewer and a Single Split Edit Point in the
Canvas
If you set up a split edit in the Viewer and set a single split edit point in the Canvas or
Timeline, Final Cut Pro matches the appropriate split edit point in the Timeline to the
corresponding audio or video split edit point in the Viewer; audio to audio, or video to
video. The other, overlapping media extends before or after this edit point as necessary.
This method can be used to backtime a split edit, as well.
To set a split edit in the Viewer and set a single split edit point in the Canvas or Timeline
1 Set up a split edit in the Viewer, with the audio In point preceding the video In point.
2 Set an Out point in your clip in the Viewer.
The resulting edit points
look like this.
3 Set a single split video In point in the Canvas or Timeline at the place where you want
the video of your source clip to start.
Split video In point
614 Chapter 41 Split Edits