That happened to me also. They literally passed each other by the door. But afterwards I was like PHEW - now I'm done for a while!
I had both in my room too today! Just a quick walk through though. They take notes on an iPad and then leave. Were yours formal observations where they stay awhile? I have the worst luck with observations. I mean, they always go fine. But we do a lot of cool activities in my classroom, and it seems like in the quick 1 minute visits, we're always doing the boring stuff.