Originally Posted by
JimInOhio
That's unfortunate. It wasn't all that long ago I checked a bag which I had as an inbound carry-on at the IAD midfield FIS bag drop.
I could certainly see IAD Midfield being different, as it's at best difficult to get to the "normal" check-in area from there. Duty Free liquids alone likely makes the use case you mentioned something that happens frequently, whereas at SFO they could just send the person off to the check-in counters to handle.