No, it is not Google letting you create accounts. I just tried creating versions of my addresses and nothing was allowed. I got this message: Someone already has that username. Note that we ignore periods and capitalization in usernames. Try another?
Instead Websites and services allow creating different accounts using the same e-mail, but with dots placed on different places.
Ideally a Website should strip down the dots and check whether there is already a [email protected] when someone tries to create account with [email protected].