Joseph, you are being deliberately obtuse. lilmod ulelamaid is correct– the fact that they “have a different Torah” would be what makes them apikorsim.
Now, I’m not at all convinced that sincere Reform and Conservative Jews nowadays qualify for apikorsus at all. (Too many commenters here have been saying things like “well, we can’t judge them, and they may be tinok shenishba, but nevertheless, they’re apikorsim!” which seems very backwards to me– I don’t see how a person could be both).
But– if they are apikorsim at all– it is for the reason I describe, that they “have a different Torah,” and not for the reason you describe, that they know that the Torah forbids XYZ for all Jews and knowingly and deliberately do XYZ anyway. The essence of these movements is that they reinterpret the Torah. They don’t identify with the Torah that we have. They identify with the Torah that they have created. They aren’t naughty little boys who do something they know they aren’t supposed to. The problem is much deeper than that: they don’t acknowledge in the first place that what they are doing is something that is wrong. And how can they believe that? Because, again, they don’t have our Torah, they have a different Torah.
This is what makes the liberal movements so insidious. Because they normalize and legitimize lifestyles that are inherently incompatible with our mesorah. But at the same time, I’d much rather see Jews engage with Judaism, even in this way, than reject it altogether.