Explain this Southwest Commercial to me

In all of the other episodes in Southwest's apparently neverending "Wanna Get Away?" ad campaign (which I think rivals only Flo from Progressive in wearing out their welcome) we kind of get that someone has done something really stupid and would really, really like to be able to melt into the ground and vanish from sight rather than deal with the consequences of that really stupid thing.

But in this ad, the guy who shows up and identifies Fenwick has unwittingly saved the life of every person in his defeated group except one- Fenwick.  They should all be thrilled that they managed to be incredibly loyal and brave yet because of this one guy they will get to tell their grandchildren how incredibly loyal and brave they were.  The dope looking for his shield has saved an entire army from annihilation- only one guy, Fenwick, will be sacrificed.  Which is what Fenwick wanted anyway- shouldn't he be the very first to thank this guy?  I mean, what are we supposed to think- that if the guy with the shield hadn't shown up, they all would have been spared, and now they are all going to be executed?  Because I got the opposite message.

(After all, if after the battle between the slave army and the Romans in Spartacus someone had unwittingly identified Kirk Douglas as the guy Lawrence Olivier was looking for, Spartacus would have been satisfied, Crassus would have been satisfied, and the slave army would have been sad but spared.  Instead they all get crucified.  That's a happier ending?)

So what am I missing here?