Only if you released it. You could definitely perform it in the shower without owing anything. And the 99% of your compositions that didn't wholesale mirror any specific song would be perfectly fine to release.

Now, moving from holding the model creator culpable to the user would obviously be problematic as well, since they have no way of knowing whether the output is novel or a copy paste. Some sort of filter would seem to be the solution, it should disregard output that exactly or almost exactly matches any input.