It's fake. I watched it carefully. My legit time on the Bridge is 29 min.
After 20 min the hordes get thicker and more intense until it's overwhelming.
In the video "late in their game" the hordes look like they would in the first 10 min. Even if they juggled the Health Packs up it still wouldn't be enough.
I have over 2000 hours on the game. Over 10,000 survival games played with a kill count of over 900,000 zombies.
It is the easiest Survival map and I've done 18 min by myself with the Bots but in my opinion this team didn't do 58 min.
It would take about a 140 Gigs to record the game in FRAPS which is viable.
Post the whole game from start to finish. You could covert it from AVI to FLV and still get in under the YouTube limit.