I think it is very easy to slag off the A10 pilots here, and American "ROE" in general. Yes, they made a dreadful mistake, but I can guarantee you all that it is no picnic being sat above a Troops In Contact situation. You can bet that these pilots had guys on the radio screaming for weapons to be put on the ground ASAP before they lost any more men/took any more incoming fire. The pilots will have been caught between the old rock and hard place ie. wanting to get the bombs on the ground quickly to help out the friendlies, but at the same time trying to identify everyone down there.
Many of us who have been involved in these situations will have been asked to put weaponry down VERY close to the friendlies. I know of several recent occurences where FACs have asked for heavy weapons within 100 feet of their very positions. One can only surmise that this is what happened in the situation we are discussing in this thread, however I wasn't there so can only guess.
Before slagging off the Americans any further, we must remember that they operate under differing ROE to us brits. The A10 and F16 pilots I have worked with over the years have been professional and meticulous in their work; not "gung-ho" by any means.
"If there's any doubt - don't drop." It has been beaten into me and my colleagues for years. There are times when we've come home with bombs on even though the FACs have been requesting ordnance. The difficult part is knowing when NOT to drop.