Too Much Stress
There are people who like to squeeze stress balls to let out stress. However, it seems like this guy has more issues than just that.
This happened when he squeezed it a little too hard. He needs a different way to channel his stress, methinks.
Watch Out
When you are trying, you should not leave your toolbox open. Otherwise, the guy behind is going to be in for the shock of his life.
A clean windscreen can definitely do without a heavy tool lodged in it.