I did some more testing on the torn frame issue.
It appears to be related to the preview; specifically the ml grayscale preview used in crop mode.
Canon 7D
2/23 TL build
RAW video (MLV)
crop mode
1792x1008
23.976 fps
Global Draw: ON
Preview: Auto
Overlay/Global Draw/LiveView
MLV Sound / separate WAV
I shot the back of a rocking chair, with the vertical struts filling the frame from top to bottom, and panned constantly back and forth to reveal the issue if it was present.
Test 1:
Alternated between using ml preview and Canon (hit "INFO." button to toggle between the two).
Shot 12 clips, 6 with Canon preview and 6 with ml preview.
Clips averaged 33 sec (794 frames) long, ranging from 450 to 1065 frames.
The 6 Canon preview clips were fine.
5 of the 6 ml preview clips had the torn frame issue.
Test 2:
Shot 15 clips with ml preview.
Clips averaged 12 sec (294 frames) long, ranging from 256 to 342 frames.
13 of the 15 ml preview clips had the torn frame issue.
Test 3:
Shot 11 clips with Canon preview (switched from Preview: Auto to Preview: Canon).
Clips averaged 15 sec (356 frames) long, ranging from 304 to 430 frames.
All 11 clips were ok.
Overall stats:
17/17 Canon preview clips were ok.
18/21 ml preview clips had the issue.
Notes:
1. When the clip is bad, it is usually bad all the way through, with alternating good and bad frames. Maybe 3 or 4 times, it was only bad for part of the clip.
2. In all but one of the bad clips, the tear was near the top of the frame, so if there was no motion there (static background) it wouldn't be noticed.
Let me know if you need more info/testing.