The issues starts with BA using that one Gate at ORD. when one flight is delayed the rest get knocked on. So the delay on 294 hits 298 etc etc. Pushing back into that cul-de-sac off K16 always ends up with the aircraft waiting for taxy clearance. So the following night we used K19 and it ran much better.

ORD has some strange rules around lightening in the area so that might be a factor rather than at the airport.

I also had a running goat f of a bag issued that continued into Sunday. As was in my original post.