I don't think any of this being done on accident. This country has always weighed how much "collateral damage" we can get away with. Even if it was, what is the difference? You think the people at a wedding who just had their whole family killed cares if they were targeted or it was by accident? They know who did it.
When you are constantly bombing weddings, hospitals, schools and other similar things. Whether it's accident, mistake or on purpose, it's probably time to stop and leave.