i had something like that happen in my 49 3600 one day in the rain, i was doing 45-50 and hit the brakes they pulled and spun the truck around through an intersection i though i was going to roll it. so i second you on the "it scared the holy crap out of me".
but very glad to here you made it safe. are they tires any of the brands just named here in the last few weeks about tread seperating?