I noticed in some cases when I get a verification code from Google it may say something along the line of:
"You should not share this code with anyone else and no one from Google will ever ask for this code."
OK, this seems like it's for security reasons, but the code is only a one use code so if you give someone it after it was used then it will not work. (May not apply to giving someone the code before use, however even if someone knows your username and password and was able to get an unused code and that person were to login a new code should be generated for the new session. Right?)
Am I missing something, is there any reason not to share the one time code, especially the part about some random stranger calling and asking for it? Also it should have long self expired before someone had the chance to call you and ask for it in the future.