Unfortunately, counter errata notations have usually been assigned to the counter, not to the game where they occurred. So, for example, the
German Heer Sergeant had mistaken combat and morale modifiers in one of the old (long out of print) games. The erratum shows up every time a scenario includes a German Heer Sergeant.
If you're unsure, the best thing to do is compare the numbers on the piece to the numbers on the counter's page in the library.
As far as the GER HMG, I usually go with the 5-5, as it's standard in the newer games.