If they happen to be in a state, like CA, that pays OT for anything over 8 hours a day (not qualified FLSA), rather than 40hrs a week (which is FLSA qualified), you may be seeing the qualified amount on the W2, and the total of all on the paystub.

But as previously mentioned, no matching this year, its kind of a free for all, but dont be surprised if next year the amount of qualified OT is much less than the stub.