Greed as in "I want more than $5250", or greed as in "I want to be the only winner"? The former is greed, the latter is douchebaggery.
Forgive me, I was on my iPad.
Barring anything like "he didn't hear or do the math by looking at the scoreboards before the last spin," all I can think of is that he wanted to win more than $5,250 on that episode. That makes a picogram more sense on Whammy since you're there just the once, but did Press Your Luck simultaneously have an appearance limit as well as a winnings limit?
I think that there must have been one of those things I listed as it would be easy to not hear or pay attention to something because it is so easy to take the thing that creates a tie, makes you a new best friend forever.
When the winnings limit was changed to $50,000, Peter had stated that the appearance limit was "5 shows or $50,000 in winnings". He also mentioned that to a contestant who was on his fifth show and told him, regardless of the outcome, it was his last show (Chris from 1984).
My first thought with this situation was not doing the math correctly, but I'll advance another theory: not knowing what the rule for a tie was. He may have thought there would be a tie-breaker where he may not come out on top.
And, yes; I'm positive the rule for a tie was spelled out in the rules packet given to the contestants before the show. But, I'll mention a bit of my own perspective: When I was on WoF in 2006, we had that big packet of rules which, among other things, explained what happened if there was a tie after the final puzzle. Even with that, and even with everyone signing a form acknowledging they read the rules, when someone in the audience asked Charlie between tapings what happened when there was a tie, I was the *only* contestant in the pool who actually knew the answer.
I kind of put it akin to somebody always commenting, "You can have a game end in a tie?!?" anytime an NFL game does just that, even though it's been a possibility for decades.
Anthony