I think his play was alright. He should use both evade buffs more and should hit crystal when nobody was guarding it. And yeah, premonition is pretty useless unless you got persevering prefixed set. Premonition isn't good until it's lvl 3/4. Should use stealth strike almost all the time.
But his team was plain outmatched. I've been in this situation plenty of times. There was little he or his team could do about it.
And for sin vs an equally buffed/geared zerk, I give the win to the zerk. Not sure about sins vs pally 1 v 1 but if that pally has battle mount, GG.
Personally, I really like the bow. When that cleric kept running from you when near death, if you were using bow, you probably could have killed it a few more times, but that's just me.