2/5 - what should the floor ruling be?

[Fat Nicky]

i found the floor ruling interesting in this hand. i won't post results yet, but here is the situation:

Pre-flop: 2 EP players limp (4 and 5 seat), button raises (1 seat), both limpers call.

flop is As 9s 5s. 1st EP bets $100, while 2nd limper is thinking in the 5 seat, the 4 seat (old guy, prob 65-70) lifts up his cards off the table in front of his face. The 5 seat calls the $100 bet. 1 seat disputes that the 5 seat saw the 4 seats cards and says something along the lines of "how can i play the hand while the 5 seat knows the 4 seats cards"

the dealer claims she was arranging the chips in front of her and didn't see the 4 seat lift his cards. the 2 seat agrees with the 1 seat. the floor is called......