Short game, kind of hard to draw conclusions from it. Generally speaking though, Erebus just has a really high damage threshold before he really starts to lose health, much higher than most DGs. That being said, I don't generally have issues crossing that threshold with UB, Rook after level 4, and Oak after level 8.
Most of the time if a game lasts to level 10 Erebus really starts to break down against oak, as the healing off of Divine Justice outpaces Bite's heal and the Penitence debuff and hastened creep waves start to tear EB down pretty fast. It's especially problematic for him when his own nightwalkers begin feeding HP and mana back to oak, I find Nature's Reckoning tears them up in conjunction with Surge since it hastens your attack and that just pushes NR over the top (NR proc kills count for Divine Justice).
UB can just outmuscle EB pretty consistently as long as he's got monk support, and Rook can generally stalemate him with a tower farm until he levels up high enough to start one-shotting minion swarms with Hammer Slam. Also God help EB if UB actually hits level 15, bite procs Acclimation every time and Putrid Flows with Ooze is going to put out 1250 AoE damage in the first 5 seconds of the fight, even full morale Nightwalkers are going to go down pretty quickly.
You were up against some pretty low DPS characters in that game. For all the talk of how crazy he is, DA really doesn't have much sustained damage... He's got one big burst every 15 seconds and Bite mitigates that pretty well, and then he flounders for the next 7 seconds while he waits on his Warp Strike, which the second bite will almost completely negate. During that whole time you've got a pack of minions wailing on him and monks healing up your HP pool which is almost always going to be larger than his, not to mention you can just when you expect burst.
So while I agree EB's extremely durable, I don't really feel this replay proves he's too durable.