OK, what's wrong with me or with this game?

I'm chasing cleaning robot in order to put you-know-what into trash can. Every time I'm leaving teleporter, the trash can is open with robot next to it. Looks OK. What should I do to prevent trash from being closed? I've tried clicking on trash, on robot, drag&dropping the helmet, everything :( Never close enough, Vella says it's to late, "won't open, that trash robot shut it tight!".

Any idea what to do? Should I execute the whole sequence faster or am I missing something?

Okay, I know what was missing here.

You need to block the passage by moving that thing - just look at the screenshot. If the corridor is blocked, it slows down the trash robot a bit and you'll be able to get to the trash can (using teleporter, of course) just a moment earlier - just enough to catch him and keep the trash open. Voilà!