Managing personal Outlook.com account settings, security, and privacy
I have read this entirely and have not found the answer. My issue is simply. I created a hotmail account when hotmail first started up a long time ago. Never had any issues with it until about 3 or 4 years ago when I found out someone from a Spanish speaking country has the EXACT same email address.
I appreciate that this is quite a long thread, but it does contain explanations. If you read nothing else, I would suggest looking at the excellent post by ¡Firedog
An explanation for your case is that 3 or 4 years ago someone from a Spanish speaking country put down your email address somewhere instead of their own. It is likely that you share similar email addresses and he made a simple mistake.
What happens if you try to sign it to Google with your original email account (not the different one you mention)? If someone else has managed to create a Google account with the email address then you can go through the Google process to recover that login or one of the other options they provide. It is a matter you need to pursue with Google.
Yes, it is definitely possible that someone else can provide your email address to a website (including Google). That is not something that Microsoft has any control over, not is it a glitch with their system.
Good luck!