So far I've found Mikael Woltorf in 3 different spots:
Old Quarter, Enemy Number One
Kain's Crest, The Rotting Baron
Kain's Crest, Zombie Street

In Mikael's description, he should be found on a hospital rooftop, which coincides with his appearance in Old Quarter but not the other locations. Still logging where I find these guys and hopefully we'll get some clarification.