You raise a good point, and thankfully, are looking to debate and not point score. The least I would expect is a formal investigation into his reason for missing this engagement. If his reason isn't valid I'd discipline him. Whether that would be dismissal would depend on the circumstances, but no mistake, the club need to be consistent with it's staff.
Alternatively, maybe he's like that internet prankster on the Aygo advert and he was there dressed as a bit of pitch...........