If he had suffered any kind of attack on Sunday night that resulted in that much blood loss, he would have been even weaker the next morning. I don't think he would have been in any condition to walk to the truck.
There may have been an accident and punishment the night before, but I don't think it necessarily means he bled as a result.
That video TS made is a mystery. Do we know for sure she recorded it on Sunday? Gannon can't be seen and I couldn't hear him say "I'm bleeding" at all. I listened closely for the beginning "B" sound and an "ing" sound at the end and I couldn't hear either one.
Anyway, he did respond to her questions and said "pinky promise," and "ok," while she was talking to him, which makes me think he was not severely injured. I don't doubt she assaulted him physically or abused him in the past, but I think all that blood was the result of the brutal beating, and possibly stabbing and shooting, on Monday.
Imo