First of all, the contestants are there to win. All of them. No one is there to make another person win.
So when the Briefcase came, the three who decided NOT to go for it assumed the chances of it being something bad or not worthy enough. They did not want it. Their choice.
Ajaz and Sangram who opted for it thought it might be worth a shot. If not winning the show at least get something. It could also be something great. Go for it.
So there is one way to best explain the voting rationale of Andy, Gauhar and non-voting voter Tanisha!
"The box has, mostly, something of bad consequence in there. Now I better vote to ensure my toughest competitor get it and suffer the consequences"
No other good intentions!