Yo i have the same issue - did you manage to solve it?
Viewing post in Stuck on the manatee/mermaid on the bridge
I understand. Well - i wrote to the gamedev yesterday on two pages, if i get an answer i will update you. Also - one time i DID manage to walk past the point where the group falls down! some bat type enemy came and absolutely mauled my group, because i was not prepared for the fight. sadly, all the times after this i kept falling down instead of seeing this enemy, i dont know what the difference was..