Daniels mostly likely either didn't know there were zero timeouts, or that the game would be over, but I still think the OC messed up and thought he had three TOs in OT instead of two. They huddled before the play and had wide receivers running deep routes, so someone other than Daniels called that play, and that play was NOT to spike the ball.
And even if the OC did stupidly call a play to throw the ball down field, either into the endzone or out of bounds, obviously you're at least going to say to your young QB, 'Uh, remember, nobody can get tackled in bounds on this play'. And that play without a doubt was stupid. Because even if Daniels did throw it, it could still result in a turnover or the receiver getting tackled in bounds. No play caller should have ever, ever, ever called that play with where they were on the field.
I think most likely Daniels is a young QB without a command presence who like a robot does what he's told without question. Which was always my Kirk Cousins nit pick actually (though even Cousins the boy scout wouldn't have followed THAT call). Obviously a good vet QB would disregard the play call and then chew out whomever called it later in the locker room.
Also, the OC, David Blough is all of 31-years-old. He's actually more inexperienced calling plays than Daniels is running them.