Oh I'm on PC. Do you have to hold down the right mouse button?
Yes click and hold but only during combat. After combat ends a downed companion will auto-revive themselves.
I think you just have to issue an order - that's how it works from the tactics screen.
No there is no way to issue an order from the tactics screen to revive a downed companion. You can however change (and I highly recommend you do change this) the health percentage a companion has in order for the AI have them drink a healing pot. I have all but two of my companions set to 10% so they pretty much fight until they are dead before they drink and if one dies during combat they will drink a health pot as soon as they revive themselves.
On xbox the reviving mechanism works just like it does in Mass Effect 3. Select the NPC/coplayer you want to revive and hold down the "A" button on xbox. Not sure what it is on other platforms.
As far as being stuck in combat, you may need to save and reload.
The "injured" thing will show up when they are below some percentage of health. They will stay that way until they drink a health potion or rest/fast travel to a camp. When they drink a health potion is determined on the behavoir screen.
He said the game had kept him in a "combat" status ...therefore there is no way to save the game.
Well, there is a spell in the Spirit line that resurrects. They do so after a battle. And if you walk up near them and hit the appropriate button.
Sounds like that might be a bug.
Yes there is a spell that you can take in the Spirit tree called Revive to rez a fallen ally. I can't see why you'd take it with the way combat and rezzing works though.
Say I have Bull, Solas and Sera in my party. As a Reaver, Bull is (for me at least) almost always near death or dies during combat. While I did give Solas the spell Revive to rez folks (and have since respec'd him out of it,) unless you set it as a priority spell (and why would you) he will not take the time to stop dpsing and rez Bull ...whereas you can stop dpsing during combat and run over to dead Bull's body and hold the right mouse button (on PC, not sure what Xbox/PS buttons are used) to revive him while Sera and Solas continue to dps whatever mobs are there.
Or you can hopefully kill everything that's been trying to kill your party and then Bull will auto-revive once combat is over. It's just wasting precious Mana to have Solas cast Revive on Bull when you can very easily do it yourself without wasting any Mana at all.