The hardcoded logic looks correct, I suspect a Mixer issue.
TSAGE: Ringworld2 - F5 doesn't create a save game the first time
Fixed in ec62d1e99fff011555357a0e13eb530d23080eaf
RINGWORLD2: Glitch when Nej rises/crouches after guard is stunned
Fixed in ec37a542edbe3d4a7d1301abd34532afe5d383b2
SCI: LB2 - Pterodactical door can be opened while wired shut
Ringworld2: Pathfinding/Teleportation bug
Fixed in 68eb280116eca9154b71159af3f6c9160b6315a7