You know, I had a thought about something regarding Glenn...
Bear with the scenario here...
1. We know that zombies only eat fresh catch, not each other.
2. We know from season 1 (Glenn and Rick), season 2 (Michonne), and season 5 (Carol) that the Zs can be decoyed by smearing yourself up with Z guts.
3. We know from all of the seasons that the Zeds are getting progressively... squishier. As they were herding the mass out of the quarry some of them were literally exploding against that corrugated wall that they built around that curve in the road as they were crushed up against it by the Zs in back of them. Sort of like the people in front of the stage at a rap concert when the people in the back surge forward.
4. We know that Glenn and Nicholas were in a blind alley closed off by a fence and dumpster with Zed on both sides of the fence pushing towards the center point.
OK, here's my theory.
Glen is alive. Not in a good position, but alive, because...
As Nicholas fell and took Glenn down, Nick the Dick fell on top of Glenn. Those were Nick's guts we saw flying out.
The gunshot that NtD fired into his coconut is going to get the Zs REALLY pushing towards the center point, HARD. In fact, hard enough that the ones at the center point are pretty much going to liquify, and it's going to be a regular Blood and Guts *expletive deleted*it Storm, right on top of Glenn.
Glen is going to get covered with this stuff whether he likes it or not. He's now wearing Eau d'Zombie No. 5, and as such, while the zombies are chowing on Nick's festering carcass, Glenn literally disappears off their radar.
I'll say it again.
Glen is alive.
He's not going to be smelling too pleasant, in fact he might be so gross that Maggie pukes up lunch AND the baby, but he's alive.
That was the strangled "Help!" that Abraham, Sasha, and Darryl heard as they were motoring down the highway in the fuel truck.