I don't think Widmore ever saw Jacob, but I think he has seen MIB. Consider that the Lighthouse (Jacob's list) doesn't have Kate's name crossed out, while the cave ceiling (MIB's list) does have her name crossed out. Widmore was clearly given the name of the candidates by one of those two, and since Widmore said that his list says that Kate is off the list... Like the rest of the Others, I don't think that Widmore has ever met Jacob.
I don't think Widmore ever saw Jacob, but I think he has seen MIB. Consider that the Lighthouse (Jacob's list) doesn't have Kate's name crossed out, while the cave ceiling (MIB's list) does have her name crossed out. Widmore was clearly given the name of the candidates by one of those two, and since Widmore said that his list says that Kate is off the list... Like the rest of the Others, I don't think that Widmore has ever met Jacob.