So what were the situations for the other two GDP?
Since you apparentely couldn't be bothered to answer, and I am quite interested, I looked it up.
Cabrera's first double play of the year was in the top of the third in New York, with no outs and runners on first and second. The game was a scoreless tie, so I would definitely agree that this was a fairly key situation. BR also lists this as a high leverage situation.
His second double play was in the bottom of eight inning in Toronto, against the Orioles. The Orioles were up by four, and there were no outs, with a runner on first. While BR lists this as a medium leverage situation, I wouldn't really call it a "key" situation.
While this is all very interesting, it's certainly not a meaningful sample size to say that he has a "habit" of grounding into double play in key situations. Only one of his 37 PAs in high-leverage situations has resulted in a GDP.