This has happened to me twice in Spartan Ops history... the first was a Watcher that got "stuck" in a pillar on the mission Gagarin back in episode 1 (or was it 2?). I tried everything to get to him, including grenades, explosives, melee, and just plain shooting. Nothing worked. I had to restart the level.
The second time was the same that you mentioned TC. Earlier today, I was playing Victory Lap, and I came across a Knight that was "stuck" in a door (that would not open), with only the binary rifle sticking out and flailing around. Again, I tried everything, but nothing worked to get him unstuck or kill him. So again, I had to restart. An annoying glitch (especially when you're playing legendary)...
IRON MAIDEN IS MY RELIGION! Gamertag: Demigod Elessar
I had a crawler spawn UNDER the ground in valhalla. we tried everything to kill it, but nothing worked. still beats fighting mini elites.
A while back, I was playing Hairy Call solo on Legendary, and had gone through the entire mission until there were only like two Elites left before extraction. I blew up one with a grenade, but apparently the force of the explosion was suck that it forced the other (who survived) through the map and into glitchspace where I couldn't get to him. So I had to redo the entire mission over from the beginning.
"Wall of Text'D!" --- oldskoolplayr76 "POwned again." --- blight family