Thank you for your advice. I've never thought about logging out of my google account. What I usually do is open a browser that I never use which mostly is Firefox, clear the cache and cookies and do the search for google.com/ncr and the other big ones like co.uk, com.au etc.
Next time I will wait for a good while before I open my mouth, that's for sure. But I just wanted to know if it was a normal Google incident or only me.
I've search and find some interesting stuff called Yo-Yo Ranking and Google Dancing kind of terms. Not sure if it's the case.