Sounds like pretty clear voter intimidation to me. I bet if we follow it back far enough we get directly to DeSantis' office.
I went through an entire training for collecting signatures in AZ this year. I've never heard of a state sending police to verify signatures in any way shape or form. The various state laws around signatures on petitions are usually pretty clear. If there is a question at all about whether it follows the requirements, it's not counted.
This is why those petitions usually need 3-4x the minimum number of signatures to make sure it's actually on the ballot. States love invalidating signatures for the simplest things.