Collin:
Collin does not notice anything unusual himself, but he was with Dave, who he does see go over to help Mueki, who he would not have otherwise located.
Dave:
As far as you can tell, the support seems strong enough to hold should someone try to use a rope to climb up. However, if the support were to be pulled down, it seems likely that the pokémon could be injured, and possibly cause more structural damage.
Blake:
The ball manages to hit the crab, as intended, and absorbs the pokémon inside it. The ball shakes quite a bit, and just as Blake is certain it was going to break open, the ball indicates the capture as a success.
Spoiler
Show
Male Krabby, Level 15, Bashful, Hyper Cutter
Mueki:
After the net is held out, the Dratini seems more than happy to jump down into it's safety.