American Airlines, LAX/BOS/LHR, about a month ago.
Boston has a problem in some wind conditions where they end up with most of the runways unusable; the effect on airline schedules is as expected.
I had about 1.5 hours to connect in Boston. We were held for 3 hours in LAX waiting for Boston to accept us, and arrived about 2.5 hours late in Boston.
Flights out of Boston were running about 1.5 hours delayed when I left LAX, so I wasn't holding out much hope for a connection.
When we arrived at Boston the crew announced firmly that passengers not transferring should wait for those who were transferring, and about 17 of us hotfooted it off the aircraft, across the concourse, and onto the waiting flight to LHR which AA had held for us a bit longer than the weather demanded.
About 15 minutes later we left, and I felt glad I would be getting to London, even if my bags seemed unlikely to follow me.
When I arrived in London, definitely feeling rather tetchy, one of my bags emerged onto the luggage belt, and I waited for the other one, still expecting something to have gone badly wrong.
After a few minutes a cheery AA baggage handler walked up with the other bag.
I really wasn't expecting that. Some people in the AA baggage handling Boston (and probably also the LAX, for initially loading the bags sensibly) were definitely doing their jobs that night.