I defer to other mods to handle bng complaints, but looks like this was missed for quite a while.
"- Girders may be used for bouncing purposes only. Destroy the girder before continuing if placed incorrectly."
If that's been the same rule since this game, I'm guessing the literal interpretation would mean you can't teleport behind the girder, and if you do, you need to destroy it (right?), which Rivivia didn't do. Or is the rule only valid until teleporting away? (seems like a bad loophole though). Again I defer to other mod opinions.