Well, that's the old Leica magic for you.(posted 9781 days ago)Sure, it sounds as if perhaps the films might have been under-developed, giving a lower contrast and thus greater latitude. Another possibility lies in the lenses. Are you used to them, or are they new to you? I use some old screw-thread Lieca lenses, and they have much lower contrast than my newer Nikon SLR lenses. One effect of these old lenses is to spread a bit of light all over the image. This has hardly any effect on the hightlights, but raises the tone in totally dark shadows equivalant to about one stop. This means, I suppose, that it is more tolerant of a little under-exposure.
Another possibility is that you are better than you think.