Turbo Brisket?

Think I might have got a hold of a turbo brisket. Really surprised me how fast it cooked. I was curious if anyone else has had the same thing happen?
I normally cook flats in the 8lb range. They have always been perdictable at 1.5 hrs per pound at 250 dome temp. Sometimes a little quicker, sometimes a little longer. Always within that general time frame.

Cooked my first packer cut last night. It was a little over ten pounds, so I was figuring on a 15 hour cook. I put it on the egg around 9:30 last night. Guru probe cliped to the dome thermometer (set at 250). Both guru and tel-tru were reading the same. Both were calibrated.

I had my maverick remote unit's alarm set to sound at 170 degrees (This is when I like to foil my brisket). I was woken at 3:00 this morning. I thought this can't be right, the brisket couldn't have broken the plateau that fast. I figured I had the tip of the probe in a fatty area. After re-positioning I found that wasn't the case. Best I could do was find an area of the meat registering 168.

My brisket hit 190 by 6:30 a.m. I didn't think it would get there till around 12:00 or 1:00. It turned out great, but I am curious. Is this someting that can be expected with packers?

I have heard of turbo butts. Did I have a turbo Brisket? When timing future cooks, should I figure whole packers at closer to 1 hr a pound.

Thanks
Mike