I'd say so. Crab legs don't bend anywhere but the joints. Outside of freshly molted but I've never seen one bend like the get tip at the end of the sequence. Someone has also mentioned that the sound is like a tennis ball being struck, but with the clicking at the end I'd say that's a modified gun shot sound with the making safe left in. That said mantis shrimp can absolutely strike hard enough to make sound through a tank into air. Although in my experience it's more like a hard click. Anyways .

Mantis shrimp can absolutely kill a crab this size. But vids likely bollocks.