×Don't be so agressive...

×you need to be agressive. But. sooner rather than later, you must atone for your sins

to be a bit less oblique:

×If you could somehow produce a monster after the green door has opened the room would still count as uncompleted if you would leave the room without killing that monster.

×Well, yeah, of course it's going to be intact.

What matters is if the tar mother is still alive.

If not: restore to when she was, kill her, stab tar on your way out and don't kill the babies before exiting.

If the tar mother is alive, you can clear the whole blob by letting it regrow and that lets you exit to the south.