Looking at how this hand played out

600/1200 blind with a 200 ante

player 1 raises to 3000 with AA

Lane goes over the top on a pure steal to 20000 with 54

seat 9 goes all in for 35000 with KK

seat 1 calls the all in for 32000

This puts 94600 in the pot and Lane has to call 15000 (Lane could well afford due to the size of his stack) giving him odds of just over 6-1 on his 45, ample pot odds to call with a connected hand

The flop comes A 7 3 giving seat one the nuts and Lane a gutshot str8 draw. Here in my opinion is where seat 1 makes the error, he only has 31000 left and tries to bet 20000, he may as well have shoved all his chips in right here as he definatley a monster favorite to win this hand (imo he is at least a 90% fav) but he tries to bet 20000 and ends up making a very silly error of a string bet and only bets 10000 into the pot. Now Lane is looking at hitting a 6 on the turn which is 4 in 45 or approx 11-1 the pot with players 1's bet meanwhile is offering him about 12-1 (119200 to 10000) so its the correct pot odds to call with his sized stack. Had player 1 shoved all 31000 in Lane would have only had odds of about 4.5-1 in the pot and would be about 7-1 to hit his 6 with either turn or river and should not have called. or if he did would be gambling against the odds. He may have called simply on the size of his stack but not knowing how Lane plays can't be sure.

Regards

Andy