That was obvious from the fact that his 'homies' decided to seek revenge upon QT by looting and burning it to the ground, while painting SNITCHES GET STITCHES on the wall. It was a warning to them and all other businesses.
Even Mike's parents are saying that the fact he committed a robbery shouldn't matter, it's that somebody called the cops.
The store that got looted and burned wasn't the same store that they robbed. But I do think the cop surprised them, and they panicked and got stupid.