Most of my falls were getting used to the pedals and not clipping out in time and falling over at stop signs. I have had a couple of instances where I forgot something-like leaving my gloves on my back rack. I stopped in a parking lot and was so concerned about getting the gloves before they fell of the rack that I forgot to unclip.
I've been having a problem where my old(20 year old)allen wrench was not fitting snug enough into one of the bolts on my shoes so that I could tighen it properly. But I've just been nursing it along.
Yesterday I came up to the intersection of a busy access road. I couldn't unclip my right foot because the cleat was loose! I had the presence of mind to unclip the left foot and hobbled over to a grassy area so I could lean the bike over. Once I did that then was able to get my foot out of the shoe and then fix the problem.
My next stop was at a nearby local bike shop and got a 3 way allen wrench and that solved the problem.
I strongly recommend the Forte Campus pedals from Performance. Clipless on one side and platform on the other. Extremely easy to use, never get in the situation where I can't find the right side. I have them on my old Centurion and my new LHT.