You said that you countersteered. That is usually for making a quick tweek of the handlebars to avoid something on the road. Doing this kinda makes the rear end fish tail then track to the side that you pushed on.
If you were doing a dirt track kind of drive through the corner, there could have been something on the road that you got into, I.E. bird crap, oil or radiator juice, gravel etc.
I'm inclined to think you were pushing it and maybe leaned the bike enough to catch some side tread that hadn't been roughed up yet. Sorta like a new tire.

 

Low air pressure could be the culprit, had it happen once and I keep an eye on the tire pressure regularly. We have very few straight roads around here!

 

look at the front tire for scrubbing perhaps you reached the traction limits of the tire

 

I also wondered about putting the foot down. You're not on a MX bike, the feet belong on the pegs.

 

Not a smart or safe thing to do!

 

Thanks fellas, good things to keep in mind. I'll check that tire out.

 

counter steering is used for curves and missing objects in the road...push right ...go right...sit on the bike with motor off...push right and feal the bike lean over right...also slow down

 

well, something like this happened to me abt one month ago and the most important thing is ur ok!

 

The best answer here ! And please keep your feet off the ground while the bike is moving, 500 pounds of metal moving at 35-40 mph/one little skinny ankle bone what do think is gonna win that battle?

 

Is counter steering now the norm? While in the military I had to attend "motorcycle defensive driving course" once every three years. Everytime the course instructor taught counter steering as an evasive maneuver to avoid objects in the road, i.e. critters, stuff falling off vehicles in front of you, stuff like that. Re-evaluate your techniques and practice.