tournament ethics/strategy question

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The following took place in a tournament I recently played:

4 players left. 3 make the money. UG calls, button calls, SB moves in for about 2X big blind more, BB folds, UG calls. Button now moves all in. Button shows 7's.

The outcome is unimportant. My question is whether the button should just call and check down with UG, or if he should make a play to get it heads up since what was in the middle represented a significant % of the chips in play. I remember a similar hand on PSI 1 where TJ moved in and Howard Lederer seemed less than pleased. Please don't critique the rest of the hand (I was the BB). My initial sense was that it should have been called/checked down, but I want to hear what others have to say.

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