Re Garrett Adelstein and Robbi Jade Lew, why do they 're-deal' or whatchamacallit the river from ace of spades to 9 of diamonds? See 4:16 onwards here. I've seen things like this in, say, blackjack, but poker I've never seen...at least texas hold 'em. I think I've seen other poker variants that are like this.
Guess: Somehow there's a rule where all players who haven't folded can agree to re-deal.