Found a second CCTV video from the USAJet crash last year in Saltillo, Mexico.

Put together a video with some of my observations of the crash. From what I saw, at some point in the approach or possibly missed approach, the crew allowed the jet to get slow and stall. During the subsequent stall recovery one of the engines suffered a compressor stall (common due to the high angle of attack and disrupted airflow to the engines). The a/c rolls first to the left, then back to the right before impacting the ground. While it is confirmed that the a/c hit power lines, the time gap between the 'flash' and when the lights go out is too long, therefore I believe the flash is the aforementioned compressor stall.

I haven't been able to find any NTSB or Mexican DGAC reports (other than prelim/factuals) on the actual cause of the crash. Interestingly enough, one Mexican news site had posted an article last fall suggesting there was a "racial dispute" between the crew prior to the crash:

http://www.zocalo.com.mx/seccion/articulo/pleito-en-la-cabina-causa-el-avionazo/