Whatever that elder says or does, you did the right thing. "Return evil for evil to no one but pay back evil with good." Whatever your beliefs, its just basic human decency to want to help someone in need. Its a lesson the JWs could stand to learn.
Something similar once happened to me. A couple years after I went totally inactive, I came across a car stalled at the side of the road. Turns out it was a carload of JWs out in service whose crappy old car had finally give out. (Damn that Satan!) So I pulled over and offered to take the group back to my house, not even a quarter mile down the road, to wait for a ride or drive them back to the hall if they preferred (four or five miles out of my way). They chose the hall so I dropped them off there. One of the group was an elder who thanked you-know-who for sending me. No, I just happened to be passing by on a road I drove every day and stopped to help, like any decent person would.