I asked the Stew 'wassup' as we were disembarking and she just replied something about "another aircraft" in the vicinity -- never did learn whether it was a runway incursion or what.
Personally I don’t miss flying .. had enough close ones, getting ready to land in Philly on puddlejumper airlines one time out of Islip, solo passenger so I had choice of seat, two young guys flying a twin fokker.. all set to land at Philly and a big prop plane pulls out and takes off right in front of us .. we did the goose it, pull hard and go,,, E ticket ride for a second or two..
I had a very similar experience over Logan, on Runway 9, specifically, but the pilot came on the PA and told us that there was someone who hadn’t quite cleared the runway or some such. I spent some time in the Logan control tower (long story) with some Lincoln Lab guys and it was illuminating. The LL guys had a surface detection radar that integrated ATC information and announced a warning every time it thought that an ATC separation rule was violated on the airport surface. For just about every landing on Runway 9 that day, a warning was more the norm than the exception. There is a taxiway across the begining (west end) of runway 9, and planes crossed it routinely, often clearing it only seconds before another planed landed behind it. Pilots on approach always landed well long on that runway, assuming that someone would be in the taxiway.
The ATC controllers regarded us, the LL guys and their toy with studied indifference, bordering on mild hostility. Of course FAA ATC personnel tend to be hostile to anyone intruding on their turf.