Playing as axis. Got to the "Manor ambush" mission where renegade germans ambush your team at the start. Rough stuff, but I managed to fight it off by flanking left of the manor and taking out any enemies that dared to follow.

So, here's the problem:
In the ambush my sniper (Tad something, "the little guy") got downed and I had to leave him at the starting point. After getting rid of all the enemies and going back to the starting area to carry him out of there, the body was gone! I could select him and it would show where he fell, but there was no body. Am I doomed to lose him now, or is there any way around this?
Starting the mission over again would be kinda annoying. Good and challenging mission, but I'd rather not do it again.

Loving the game BTW. Never had the opportunity to play it back when it came out.

What difficulty are you playing on? It sounds like he is unconsious at the end of the mission and not actually dead. If your playing on normal difficulty and your sniper is still alive you can safely leave the mission area and he will be revived. If your playing on any other difficulty I think you may be out of luck unfortunately.

Playing on normal. I understood that you have to literally carry a body out of the mission area to keep him alive if he/her is taken out. This happened in the next mission, the factory mission where you get your first PKs, as Olli got taken out and I had to use Gunar to carry him out of there. Kinda pity as I couldn't loot all those great weapons properly 'cause of that.
If the body disappears for some bizarre reason, you can't carry him/her out of there, thus leading to that persons death. That's how I understood the wounded/downed mechanic.

Going back to the manor mission, I restarted it and tried different tactic by camping outside of the gates and spamming nades with my main engineer "Lock" and Olli as others provided covering fire behind the car and across the street. Traitor got away, but that was the only bad thing about the mission.

That's good to know. Thanks for answer!
Ragdoll physics going crazy is always hilarious, but it's understandable when devs wan't to get rid of it.