> They don't do ota updates for planes

Could have been the Electronic Flight Bag, those can run commodity OSs. I can see an OTA failing there and it needing an OS reinstall. It'd be odd, but not impossible.

Seems like it would save a lot of time, energy, and money if they did (assuming they had the procedure worked out). Push out an update while it's sitting at the gate, powered down, instead of taking it out of service and having to bring it into a hangar (where space is already limited).

This is a plane, not a consumer device

Nothing gets changed unless it's for maintenance or airworthiness reasons (or fuel economy)

Updates can be done during scheduled maintenance if there's a good reason for it (see above) or if it's really something urgent it is done overnight if possible or the plane gets scheduled for this specific maintenance