I watched that episode too. Pretty cool.

Does anyone know why after they made a cast and were stripping the fly
back in, they had their rod tips in the water? Was that to give the fly
the right action? I suppose I imagined the fly moving in a more or less
parallel motion to the bottom, when stripped in that manner, in stead
of it being brought to the surface?
Is this the correct assumption?

Anyway I'd never seen that technique before, any thoughts?

thanks,
-Ethan