If he's bragging about 8 hours of standby then he's either confused or a troll. On the other hand some people have, apparently genuinely, struggled to get 8 hours of standby from this particular model, so he may have been refuting this with personal experience and everyone's got confused.

I'm not sure we're any closer to any actual conclusions about how battery hungry the Evo actually is, what problems it might have and what kind of usage triggers them.