kill pots

I recently played 5-10/kill hold'em at Foxwoods. There were 3 or 4 players I think were local regulars who played very tight and were seldom involved in any pots. HOWEVER,in every kill pot they were all in there betting and raising! Would this be chance or strategy?

Sometimes in kill games certain players are more attracted to the bigger pots. Thus they tend to play very tight in the non-kill/small pots and are too loose in the kill/big pots.