Well I think I ran into a bug a few more tests and I'll know for sure. I was customizing at Image as Designed once done I left and found out I had been under attack for a couple minutes. I went outside and not a single person was around no attackers, no pedestrians, or saints. After the remaining 2 minutes were up I looked around and not a single person was around no parked vehicles either. Look around a little longer and found two people at a stop light but neither moved when it was green or when I shot their vehicles. I stole one of them that got a reaction of them running off scared. Drove around for awhile then was invaded again but not a single enemy showed up I couldn't even spawn my cars as it had been disabled for some time. After that I saved but I haven't reloaded that save yet.
I thought I was taking pictures of it as it was happening but I was pressing the screenshot button instead of f12. So no pics if it does happen again I'll post the pictures up.