In reply to M1EYP:
I’m sure such a bizarre coincidence would be
unlikely to happen again anyway.
On the contrary I think it is very likely if there is no change in protocol. There is a significant latency between changes to the spot database and their actual appearance, and significant skew in that latency as seen by different moderators. The window of opportunity for this kind of error is really quite wide.
Sometimes if I enter a spot and then find somebody else has already done it, I remove my own. But I’ve often worried that the other person might think the same way! Normally I will only remove my own if it is later than the other.
Exact duplicates of the kind you get with dodgy mobile phone connections could be filtered in software very easily, and I think should be.