Did that really need guessing? Contacts to the left were very very bad. Having known what the rest of the population claimed not to have known was even worse. There was no need to make a difference between SS and Wehrmacht during the 50's: both wasn't embarassing, let alone a career-killer or so. That only changed during the Auschwitz trials in the early 60's. The CDU called Willy Brandt a traitor until far into the sixties, by the way.