Originally Posted by
pallen
In my experience, sometimes the cause of the flat is easily spotted, and sometimes its not.
I agree. I am pretty neurotic, and unless I can find the culprit shard, I don't feel comfortable putting a new tube or patched tube back on. I usually will take the tire off completely and carefully inspect the inside of the tire (bending it as I go) to find and remove the bad actor.
Obviously this does not apply to those rare pinch ("snakebite") flats.