Sounds like a freak accident , could have snagged in the mouth as line drug on trotline ? Not saying he could not have bit it .
I saw couple guys on Nimrod throwing spinnerbaits once that got real excited . One tossed a spinner over a trotline with a huge Buffalo on it . When it spooked and boiled the water he says ''Did you see that &*^ Bass ?'' I almost fell over laughing cause I had already seen the Buffalo as line was shallow .