Hello,
Many people tend to think in terms of regexes, not in terms of wildcards. In man sudoers in section "Wildcards" it is written:
    "Note that these are not regular expressions." 
but this is not enough to shift some people's thinking.

Yesterday I decided to add a new stanza to my sudoers file and use regexes in it. I have read in the manual:
    "Note that these are not regular expressions." 
and understood that sentence but nevertheless I intuitively used regexes instead of wildcards in that stanza.

Therefore, the man page should pronounce more clearly that wildcards do not work as regexes. For example it could read:

"Note that wildcards in sudoers do not work like regexes. For example:
     [a-zA-Z]*
matches any string that begins with a letter, even if it contains spaces, tabs or other weird characters.
Furthermore, the following command specification
     /usr/bin/passwd [a-z]*
would match
     /usr/bin/passwd user1 -a -s root
so please be careful"