Something I've been curious about this whole time...did Brock get overconfident from the complimenting he received from that lady? If so, then this episode has something that's been *long* overdue...Brock finally getting cocky, then getting crushed as a result of it(which means that Ash and May are no longer alone in that department)!
Bow chicka bow bow. (Goes into "Cuban Pete" mode and begins awaiting the day that Misty gets well and truly *whalloped* by Ash in a battle, with no prize for second place this time!)
Marshtomp using Protect gets another "About time!" from me, given that it's one of Marshie's *natural* moves. I can certainly see how a Dig/Shadow Ball Eevee would cause major problems for the mud fish, especially if Brock got overreliant on Protect, of which the effectiveness breaks down over consecutive usage.
I wonder how Brock's would-be girlfriend took the sight of his collapse? I presume that it wasn't pretty(go back to Lucy, dude, and give Ash and May your cookbooks).