The BSA system uses volunteers - mere humans who can and do make mistakes despite their training. (We just had a B of R "postponed" when the candidate showed up in "old" (pre-2010 I think) trousers and a brand new shirt. ("Out of uniform"). Turns out the chair of the board had personal ideas that he felt trumped National "guidance" on B of Rs.
But mere humans went to the moon, built space stations, summited Everest, went to the Marina Trench, etc. We are talking simple, simple code here. It is my no means rocket science.
BSA should know how long it takes to process recharters. BSA should know that Scouts will turn 18 during the time it takes to process recharters. BSA should know Eagle is the most important rank in Scouting. BSA should have a WELL ESTABLISHED process for dealing with how they manage the applications of those who turned 18 during recharter. Not buying "they are only human" excuse.
Even squirrels know winter comes each year. Let'f not assume BSA staff are not smarter than the lowly squirrel.