They mentioned a 2 in. thick sheet of rain falling, which is ~288 cubic in. per 1 foot x 1 foot area, about 10 lbs of water. Falling as a flat sheet at terminal velocity would hit you with a force of 127 newtons. What that means as far as injuries go I have no idea. I'm sure it'd cause a nasty headache at the least though.

Fair warning, I'm terrible at math so I could be completely wrong