This is referring to eating meat from a kosher animal that was not shechted. Rambam (Ma'achalot Asurot 9:6) writes that there is a prohibition to cook them together but there is no prohibition to eat them together. Presumably he is referring to the Torah issur of eating milk and meat cooked together. The question here is if there is rabbinical prohibition on eating dairy after eating this meat.
Perhaps this would depend on whether the rabbinical prohibition is contingent on there being a Torah level prohibition on eating them together (which is not the case here), or perhaps they forbade it since there is a prohibition to cook them together.
A well-sourced answer would be appreciated.
Not sure if this the place to add this (my apologies to the moderators.) As opposed to the Mor VeOhalot who is stringent Minchat Yitzchak permits this (9:79 end of Aleph).