While it never happened to me in Inat to that extent, I have had situations where I THOUGHT the system had “frozen” or was lagging and tried to save/post whichever thing I was trying to do multiple times, sometimes trying to switch my input to see if that worked, only to realise later that it did post it… each time.
The only reason it doesn’t happen to me on Inat nowadays is that I learned to refresh the page instead of spamming inputs, but I can easily see myself doing that in accident and never finding out when I was younger. Inat does tend to “freeze” on the “processing” step of inputs for me if I don’t refresh the page after waking up the computer from its overnight slumber.
If you find that it was not an error and the user continues doing that in other observations, you could contact a curator to take action about it.