Yep, that was Riichi and Jiro, it was nice seeing Jiro as the main robber, i think it's funny that in for example B-Fighter, Janperson, nearly every single episode you could get a climpse of a JAC member either as a villain/henchman or a as innocent bystander.
Now a days it's mostly Jun, Kaneda or Yokoyama, which is great, but seeing guys like Seiji, Jiro just adds a certain something to a scene.
BTW, I still think it's wierd that Yokoyama had a cameo in OOO/Den-O and not Seiji and Jiro, the two previous main Kamen Rider suit actors.