Originally Posted by
CKBA
My concern is that the checkin staff at LHR for our return might also not be conversant in the details as well and deny boarding. I'm not expecting folks to know all the regulations, but there should be an internal wiki that can be checked. Furthermore, I cannot believe that this is the first case BA has dealt with where a US visa/green card has been extended beyond it's expiracy date due to the covid situation.
At the risk of veering further from the topic, I can answer your concerns:
LHR has its own US DHS team. If there are any problems, they can be resolved then and there, and permission can be granted to override any nay-saying computer if they see fit. They are fully aware of the US entry requirements and exceptions. Check in staff have access to that team, call centre staff do not.