Before Seb fully mounted him—where Jay would be lying flat on his back as Seb was sitting down on him with all of his weight—he took him down by grabbing hold of his right ankle, pulling it towards him while using his other hand to push on his torso. It was all done in a quick but forceful motion, probably even making his opponent have a small concussion due to hitting his head when his feet left the floor.
There was a difference between hitting your head in those wobbly or shaky mats from the WWE or something similar to hitting your head in solid rock or concrete, because if wrestlers from that show performed those stunts on stone or solid concrete, they'd need more than ice or Ibuprofen to remedy that.