This sounds like your track may be off by a single frame or the aspect ratio is not quite lining up.
When you paste or import your mocha data into the final composite or edit, make sure you are pasting or loading your data in at the first frame of the clip, otherwise your data will not line up.
Project settings such as frame rate, dimensions and pixel aspect ratio must be match between your mocha project and your destination software. Make sure these values match the settings in your compositor or editor and inside of mocha, otherwise your tracking data will not match when you export it.
If your are using Adobe After Effects, the target layer you are pasting data to should also be the same size as your AE composition. A good After Effects troubleshooting tip: create a new solid that is the same size as your composition. Paste your track or roto shape data to this layer. If it does not line up, the issue is mostly likely a project mismatch.
If that still doesn’t fix it, you can send me the shot and I can see what’s up.
It’s pretty hard for me to see any slippage because of the youtube compression. Have you tried nudging your keyframes forward or backwards one frame? It was hard to see the head track solidness in the recording, is the head track rock solid in mocha? If so, definitely just try nudging those keyframes.