I think you are both partially correct. Either the government, or some ambitious political grifter who sees the writing on the wall, and manipulates circumstances to his advantage, are going to keep collecting taxes for as long as possible, before finally leaving. It will be the very last thing they give up, long after they've given up everything else.

I never said they withdraw their full military and tax collecting officials. They leave a skeleton crew to collect taxes, and let everything else fall apart.

Matter of fact I'm pretty sure that's an accurate description of the collapse of rome. Shit took a thousand years for a reason.