Ford used car warranty contract

So my co workers Ford compact 4 door(don't know the model).
Transmission has an internal module failing causing the car to shut off.
Couple of weeks in the garage they found the issue and the Trans has to pulled as far as I understand.
He just told me today that ford won't cover the repair since he didn't have the air filter change per the contract warranty. He's now taking out a loan to get the $1700.00 repair!!!
He stated the warranty has a contract for maintenance that must be followed.

I've never heard of this, what say you?

 

This is crazy.... Then again some manufacturing companies will place some unassuming task like if you don't scratch your left ass cheek, before your right one at 12:00 noon on the 2nd Saturday of the month this will null and void your warranty. Having to fork our $1700 for the repair, might as well get one from the salvage yard... They're often $700 probably nothing wrong with them, since the vehicle's engine decided to melt down prematurely.