Yeah...
It was also super easy.
How easy, you ask?
Well, we played through it with two PCs. (We had a third for a couple of sessions, but we definitely didn't need him.) Two PCs, and the DM didn't scale down the adventure. In fact, about halfway through, he started adding stuff.
Wow... 2 pcs... something seriously wasn't working there. That's crazy!!! And no healer? What was happening that made you so invulnerable to the monster's attacks exactly. What do you think was going wrong from your point of view? I'd like to avoid this kind of thing if my group ever reaches these levels.