Proximity at the time of the event isn't always a good indicator either way, I live a very short walk from the attack last weekend and am usually in that location around those times regularly, but that day was quite a few miles away - there was still value in me checking myself as safe even if I wasn't physically there.

Needs to be some blend of proximity at that time/frequency of visit. Facebook probably stores all of this in any case, so a bit more tweaking on their part will make it easier to deal with.