Today exploits like this are impossible against even average players
As people have noted, the bet sizes before the river are much larger than what would happen in a well-played game today. I believe every action by both players before the river is a huge mistake relative to theoretically correct poker. So something like this exact hand would never play out between two competent players today.
However, the core problem is that one player has shoved the river and the other player beats all missed draws and no value, which is still a common situation. Since the prizes are $100k or $0, and the stacks will be roughly even if Ungar folds on the river, he needs to win more than 50% of the time to profitably call. Do top players ever bluff too much in this situation, and have their opponents profitably call them off? Sure, that happens a lot even at high stakes. Doug Polk recently had a video where he described how he lost a high stakes heads up pot to Jungleman in a similar situation.
1) Ungar folds, he is left with about half the chips in play, so about 50% odds of winning the tournament, and EV of ~$50K.
2) Ungar calls and is right, winning $100k.
3) Ungar calls and is wrong. I forgot that he'd still have chips left and assumed that this scenario was worth $0. In fact he'll have ~20% of the chips in play left, which is worth $20K intuitively but can be confirmed here: https://www.icmpoker.com/icmcalculator/
So if Ungar calls he needs to be right X% such that
$50K = $100K * X% + $20K * (1-X%)
X ~= 38%
---------------- Stacks: Ungar: ~60,000; Matloubi: ~40,000 Blinds: 200/400 Hands: Matloubi holds 5-4 offsuit in the BB; Ungar has 10-9 offsuit in the small blind (the button).
Preflop: Ungar raises to 1,600 in the small blind, Matloubi calls.
Flop (pot 3,200): 3-3-7 rainbow Action: Matloubi checks, Ungar bets 6,000, Matloubi calls.
Turn (pot 15,200): K, board still rainbow Action: Matloubi checks, Ungar checks.
River (Pot 15,200): Q Action: Matloubi moves all in for about 32,000 and Ungar calls within a few seconds, declaring, "You've either got 4-5 or 5-6, I call." Ungar then flips up his 10-high to drag the $80,000 pot. ----------------
Not sure what your parent has in mind, but just from the choice of sizings from both sides, I doubt that many people would play either side of the hand this way nowadays. Which kind of make any analysis a bit pointless. But I'll check tonight with a solver if it has anything to say about it.
Normally you'd fold and laugh quietly to yourself because your opponent thought they bluffed you when really they had the best hand.