Zoro did indeed nod to collaborate Liam's lie.

"[i]If that's the case, I'll be passive and try to stall them out,[/i]" Shiranui sent back.
"[i]Haru's Pokémon are approaching your position,[/i]" Titania warned.  At that, Shiranui found a storeroom, entered it and clung to the ceiling.  He figured Haru knew he was around, but he didn't want anyone but the psychic allies to know his position.