Yeah I've had a wireless uplink between two Unifif AP's on the same switch, the only non Unifi switch, come up by itself and caused a loop. Unlikely that switch only had a 1G uplink to the next switch, all the rest were 10G links, so it mostly only affected devices on that switch.
Edit: thought I'd just say that since then, I always disable wireless uplink on all AP's, and the global system setting, unless it's actually used, and only on the APs that need it.
Also tinnitus from red and white bites, and more floaters from yellow.