They kept the money didn't they? Sounds a lot like fraud to me.
It's direct deposit.
You can't stop someone from putting money INTO your account.
Spending it is a different issue, but a pretty good defense would be "I don't read my bank statements and just spend whatever I've got in there."
Doesn't mean they're not AWOL losers.
And doesn't mean they don't have to pay it back (they will).
But THIS PART is probably not criminal.