I'm sorry but I have to disagree. My bike came stock with Pirelli Diablo on them. They're fine for street and spirited riding. They caught me off guard on my first ride, biting so deep that I turned too quickly.

Tires are rarely to blame. 99% of the time it's Rider Error, not tire error. Even if the tire is old, squared off or threads showing it's rider error for not changing the tire. Riding slicks on the street: rider error. Cold tires: rider error. Improper pressure: rider error.

ahhaha.. check your swing arm angle.. its possible with the tire you have on there you locked your swingarm with anti-squat not allowing any grip in the corner.
if you didnt allow cornering forces to compress the suspension at 20mph and gunned it you stood the rear end up on that corner date.
... nah im just kidding you didnt say if it was seashell roads, concrete roads, asphalt black top type roads. if there was bumps.

lets just say this
if it was in the morning and just down the road from where your ride started, a seashell road, and you didnt gradually increase the rpms through the turn, with cold tire pressures at 42 rear 36 front im not surprised that you slid out with or without any gravel, with touring tires or sport tires.