Or it could just be that the smart people who programmed the PBX made themselves a dial plan problem.
It happens.
Reminds me of the story where a man went to the police every day for over a year and confessed to a unsolved murder, then one day his wife turns up dead and he confesses to killing her, the police do not believe him.
I once had a job where whenever I would call home (which included 911 in the number) the police and fire department showed up. Never figured out why and it never got fixed.