my theory for regaining consciousness: your bloodlevel needs to reach a certain level to wake you up again.
this would explain why some people wake up on themselves after waiting for an hour (regenerating blood / "healing"), and also why people instant-wake up when getting a transfusion with blood or saline.
In my honest opinion, i think this shouldn't be considered a bug, but a feature - with some issues.
if you fall unconscious in real life, your chances to wake up again on your own, within a few minutes, are not THAT big. for that you'd normally need the help of another person, just as in dayz.
on the other hand, waking up shouldn't be bound to blood level alone, and it should be random - given that a low amount of blood should make it unlikely to wake up, a higher blood level will raise the chance, just like the other way around with falling unconscious. and waking up on your own should also be a random chance, but the chance should only raise with time moving on - starting with 0% from instant to like 75% for 1-2 hours maybe.
if you have a friendly person around, this person would have three options to wake you up:
this should improve the willingness of people to team up - leading to less KoS, leading to more intense gameplay, etc...
another thing came to my mind: anesthesia
bringing another person to unconciousness on purpose, usually to do surgery stuff.
could be knocking the person out with the fist, or use narcotic medical supply.
this could be used instead morphine to treat broken legs, benefit being it doesn't have the HIGH chance to get you addicted, downside being it will take above methods to wake up again.
before i get bashed on from all sides, i want to remind everyone that this game aim's to be hard and unforgiving (assuming that the stance on that didn't chance from mod to game), and thats exactly what i want it to be. if i want an easy game, i go play bf4.