Been there...from the airplane side. Was in my glider thermalling under a very nice CU...maybe 500ft below cloud base at about 3500ft. Heard the call from the jump plane. I check my position...I'm in the cone, but directly under a cloud, so I figure I should be OK...jumpers are not allowed to pass though clouds. Just then a black blur shoots right past my nose. So close, it was only a blur. I crank over hard to look down...and sure enough a damn crazy jumper had gone straight through the cloud. Looked around and saw all his buds seemed to avoid the cloud just fine.
I went and had a talk with the jump master when I was back down. But usual crap of "you shouldn't be in the cone" vs "you shouldn't be jumping though clouds".