I've investigated this bug a bit:
it happens only if you talked to Domino in his office earlier. Or vice versa: you can't talk to him in his office (from now on "do") if you talked to him at the end of the world (from now on "dr") already. (Of course this can happen only by jumping with the debug keys, not when actually playing the game.)
The bug is very simple: every lua file has a statement at its top like this:
This prevents the file fom being loaded two times. Now, the problem is that both dlg_domino.lua and dlg_dom2.lua, which are used respectively in do and in dr, check for "dlg_domino.lua". When you try to talk to Dom in dr the script tries to load the file dlg_dom2.lua, but that raises an error, since it thinks it was already loaded.
So, that's basically a copy and paste bug.
The solution is not so simple, instead.
* One way could be to override the function CheckFirstTime, and make it do nothing. Dirty hack.
* Another solution could be to reset the state of dlg_dialog.lua every frame or so. A really dirty hack.
* Some more dirty hack.
Unfortunately i can't think of a decent solution right now.