If your friend thinks OPEN-jamming the river is a nice play, then please ask him why he called the turn.

^ gg

Not a good play. Unless I am missing something I don't see the average recreational player folding any better hands to a half pot lead here?...

Well it's a bit odd but I think it comes down to hero thinking there is more fold equity from repping the nut flush (with nut blocker) + equity against the range that fires twice and gives up, than there is equity of AK vs opps river betting range

So my guess is that your friend felt there was enough equity to call turn planning on using any heart as a bluff and hoping to check it down on any non heart. Prob assuming he's beat if a non heart hits and villain shoves. (Opp could easily have KK, QQ, AK)

But that opp might barrel twice with 88+, AQ+ and give up on many river cards.

Maybe it's true at his level that shoving on the Heart river gets extra folds from AA or AK, or that it prevents him from getting 3barrel bluffed Off his hand, but I don't know that's enough to be worth it at mine.