Dirrell vs Abraham: Dirrell fakes concussion? (good video)

[CFH]

I don't think the fact that he didn't immediately drop means anything really. Head injuries do not follow any set pattern.

As some anecdotal evidence, when I was a kid I was slid head first into a ciderblock we were using at home plate while playing baseball. I got up and, aside from a throbbing headache, was fine for about five minutes. I then got ridiculously dizzy and nauseous and half-staggered, half-crawled my way back home. My mom rushed me to a clinic and I was diagnosed with an amnesiatic concussion (or something like that. I can't remember the specific term). I initially remembered almost nothing of what happened after I originally hit my head. The concussion was serious enough that the doctor told me to stay awake all night and instructed my mom to check on me regularly to ensure I did not pass out/fall asleep and die.