You really owe your opponent an apology.
How do I report a cheater ?
but, really, to do something against any user there must be conclusive evidences, not point in going banning accounts because they have played in some kind of surprising way
You know your opening a can of worms here.
A lot of factors come into place when reporting a cheater. Did it accur on the weekend or weekday? Was it am, or pm? Male or female?, Was it raining? Did it accur in your car?
Was a pet in the vicinity? There is a new staff person who's in charge of all administrative punishment. Her name is SCHLIMZO. 
Well I guess it's irrelevant now, but what you suggest was my experience as his later moves were lightning quick, perhaps he was just waking up ?