I kinda hmmmm’d at that too, but if you think about it, in the common definition of semi-auto today - one trigger pull, one shot, one might class a revolver with an AR-15. It’s a stretch.
In days past what we call semi-autos were more commonly called self-loading, one shot, reloads and ready for another shot. This differentiates it from say a revolver because for the next shot to ‘load’ the trigger has to be pulled again, first.
I’ve been looking all over for a nice semi-automatic bolt-action rifle.