On occasion we see DFS events on our outdoor WISP network. It's rare, but does happen. It's understandable since we use high gain sector antennas and AP's with great receive sensitivity. Not to mention these are outdoor radios with direct view of the sky.
On the other hand, we are seeing 802.11ac home routers with DFS capabilities. The router indoors has all sort of built in attenuation, walls, obstacles, etc. Would you expect to see DFS events, if any, in this scenario?