Bug, maybe?

[Todd C. Miller]

That's very odd.  I can't reproduce this on HP-UX 11.11 (or any
other system).  With a simple sudoers file that just contains:

    Defaults	runas_default=bin
    millert	ALL=ALL

$ sudo id
uid=2(bin) gid=2(bin)

So I'm not sure what might be causing the behavior you are seeing.

 - todd