Ok, this may be a silly question, but after we all looked through the rules, we found nothing to answer the question.  We played through the 1st story and as the keeper I won.  The Shogoth was making his way through the house and this is where the question arose….if an investigator passes through a space with a monster, they have to make an evade test and if they fail, the monster gets to take a whack at them…however, there are no rules that make allowances for the investigators to take a whack at a monster that is attempting to flee past them.  Is this accurate?  Are there really no rules in place to allow the investigators to attempt to take a pound of flesh off of a monster as it tries to escape past them?

Yep, investigators need to evade, monsters bully through them. Could be the investigators cower away from the monster, especially something like a Shoggoth (what, you want to get close, like hand to hand range, with that thing!?).

Scenario 2 is designed to be monster-centric. Try scenario 1 with your team—that one's pretty good all round.