It's not a medical record, it's just the police report, which means it's the police noting that BardFinn's wife claimed the fight started because he bruised her son by hitting him. Edit: For the uninitiated I'll just add this is the 'drug-addled, evil liar' of a wife (according to BardFinn), so I'm sure the average BardFinn fan will just say she made it all up and he never touched the kid.
I'll also point out if someone of Dyn's intelligence didn't see THAT hole upfront, the average r-slurred Redditor wouldn't either. They'll just see 'five year old' and 'hit so hard there were bruises' and then the soy-induced emotions take over.