Ok, this is a bit confusing.
Do you mean BF (BusinessFirst)? If so this was a CO flight and CO staff and not a United thing.
United clears upgrades on oversell by status and then if there are no more status passengers then waitlisted people get lucky.
By the sounds of this, this was Continental, and I cannot answer how CO handles OpUps, but UA does not need a concierge to do OpUps, the GAs always do them.