Don't know if you wizards will find this info useful, but here goes.
I was testing shooting in RAW (MLV) on my Canon 5D MIII using my Manfrotto USB remote control to start/stop recording (Here's the item I'm using http://www.bhphotovideo.com/c/product/853877-REG/Manfrotto_SYMPLA_MVR911ECCN_Clamp_On_Remote_Control_for.html ) I couldn't get more than 3 frames out of each attempt, with the little video symbol never changing from red to yellow or green. It would always stop and say that frames were skipped.
I discovered that I can shoot successfully, even with the Manfrotto remote control connected, as long as I hit Start/Stop on the camera itself. I still have access to focus controls etc. So, seems to be a buffer issue somehow related to hitting start/stop on the remote itself.
Not sure if other LANC controllers are affected like this.
I have the 1.2.3 Canon firmware and am using Nightly.2015Apr28.5D3123
Hope this helps.