So there's no evidence connecting him to Isil (which there generally isn't: Isil spread messages to sympathetic people telling them to do things - ask employees of one well known company who have an unlisted London office because someone wants to slit their throats). Recapping:

- The FBI has investigated and found no links that he was a patron of the club.

- He has, for a fact, murdered people in the name of Islam.

We can't know what he felt in his heart, but also we don't have any reason to believe his stated motives aren't his actual ones. It an uncomfortable fact, but a large percentage of Muslims say they believe in Sharia which holds some pretty awful beliefs about gay people (and women, and others).