Live play MTT lesson

The $200k Crypto freeroll for WSOP Main Event qualifiers (who did not reach the money) ran at Gold Coast today. An additional $20k+ of bounties was also awarded. There were roughly 90 runners, with 50 places paying. Man oh man, talk about nice overlay...

There was one hand today where I made a mistake that only could occur in live play in an MTT. I resolve to never make this mistake again. There are probably a number of dubious actions on my part in the hand, but one thing really sticks out to me.

hand #1
The villian in this hand is probably the tournament chip leader, and he has already collected 1 pro bounty for $2k. I have already made a pretty big laydown on the river to Kenna James (who is not involved in this hand) about 15 minutes earlier.
Blinds: 50/100, effective stacks T$10,000, avg stack is perhaps ~T$10,000
- preflop: folded to CO and Villain raises to T$300, Hero raises to T$1200 with AhQh, blinds fold, Villain fairly quickly calls. (2 players, T$2550 pot size)
- flop: Qd7c4h, Villain checks, Hero bets T$1500, Villain fairly quickly calls. (2 players, T$5550 pot size)
- turn: Qd7c4h7h, Villain bets T$2500, Hero tanks for ~15 seconds and calls (2 players, T$10550 pot size)
- river: Qd7c4h7hTc, Villain fumbles around with his chips, puts 8 $T500 chips out and ~3/4 second later says $T5000, dealer reaches out, counts the chips and says the player said $T5000. Villain says okay, and puts out a $T1000 chip. Hero tanks and calls all in for T$4800.

Do you see the worst mistake in this hand?

By the way, I'm pretty proud of how pathetic I was able to look when I made the T$1500 flop bet....