I think the issue with the fog created around the Tippitt murder just like the entire JFK assassination is the same:

Given the available evidence, any alternative explanation or conspiracy requires such a ludicrous arrangement of conjecture, supposition, and “alternate facts”, that even with the mistakes that were no doubt made in the original investigation, the simple explanation that Oswald did it ultimately is the only one that holds up.

I say that as a reformed conspiracy nut. There was a time some decades ago I was eating this stuff up and reading every JFK book I could get my hands on. I think I started to rethink my attitude with that crackpot who built a whole book around the idea that JFK was killed by one of his Secret Service agents whose AR15 discharged accidentally .