Swen says the jump was helped by the Tadpole... Mindflayers have psionics and this is a special tadpole.
I am assuming the tadpole is assisting the mage hand also. We will have to wait and see if that is the case.
so only the pc can jump that far or every npc you get is infected.
They all could from what I saw.
In some instances it wasn't necesary because unlike a certain Vampire wannabe, they could walk through the water, but all could jump with the same slightly goofy animation (hope they improve it and have an alternative should we be rid of the tadpole and want to jump)