You inverted the argument accidentally with your angel analogy, I think something like "we have labradors, what evidence do we have that they are not angels?" m

You inverted the argument accidentally with your angel analogy, I think something like "we have labradors, what evidence do we have that they are not angels?" matches much more closely to the thrust of their point while also highlighting what you find lacking about the argument. Edit: the important bit is that the subject already has some qualities in common with the proposed classification which is a significantly different proposition than a purely hypothetical orbital teapot