Stuck in Memento Mori Map19

http://youtu.be/dbCYZH6WMs8?t=4m21s

im stuck. the player in the video runs under the celing to the switch. but in my game the celing isnt high enough to go through. gzdoom here. did i do something wrong or did i miss a switch? :/

I guess you didn't cross this line? -> pic
The author didn't realize that you don't necessarily have to cross it to press the nearby switch. Whoops!

thanks for reply! maybe it was your hint or a script was broken. i played it again, this time faster and not killing the revenant in the middle so early, and it worked.

Me and a freind were playing splitscreen and we got stuck here.. We spent about half an hour searching the whole place up and down until we decided it was a glitch and just skipped ahead. You're not the only one to get stuck here :)