It's the more ambiguous ones I see that get people to argue about how PEDMAS is interpreted. Your example is unambiguously -4. But consider:

6 / 2 (1 + 2) = ?

I approach the problem the same as I would 6 / 2(x + y). When the multiplication is missing 2(x + y) is a single term. The implicit multiplication is part of the parenthesis and reduces the problem to 6 / 6. People who argue that you have to strictly use PEDMAS left-to-right will divide 6 / 2 first and get 9.

Neither way is wrong as long as you can explain the process but everyone wants to argue and have there be a single answer.