I eat a ton of meat, so there's that.
But eating a minimal amount of meat once in a while is still the same as eating strictly vegetarian forever, imo.
Depends on their personal opinions of course, but some of the vegetarians I know they don't not eat meat because "oh noes that individual poor baby cow died for this piece of meat" but because they want to reduce animal suffering from mass production, carbon footprint etc.
It's not like you failed because you eat bacon once, that specific animal didn't die because of you. But eating 99% less meat still has the same effect on the market demand.
I like this approach more than the moral one. A friend of mine will e.g. eat meat once a year or so when we are testing dishes from foreign cuisines.
Unless of course they end up eating like me forever, then I don't consider them vegetarian anymore