Wiktionary
tough call
n. (context chiefly US idiomatic English) A choice or judgment which is difficult to make, especially one involving only two alternatives.
Usage examples of "tough call".
As Jack and the guys moaned to each other over bourbon in the mess, it was a very tough call to set your career alight dropping powdered milk on dead African people.
GOP control of the Senate hung in the balance at the time and it wasn't a tough call.
Saving someone's ass who would easily do the same to you is a tough call.
At times of sheer stupidity like this, it seems like a tough call.