Just played this scenario. Simply put, it's absurdly deadly to any 1st level party. There's two encounters that hover around CR 5, which is just too much.
The final encounter has the BBEG with a +9 to hit for 1d10+4 damage - that's enough to one-shot just about any 1st level character. As if he's not bad enough, add in 5 additional enemies. Without seriously lucky rolls, this is a TPK waiting to happen to a APL 1 party.