Sorry to hear...as you are finding out though..they will make it right....and then some.
I put alot of arrows through my 80 pounder at 5 grains per LB with no issues whatsoever....in fact...never had a limb prob w/ BowTech actually that I can remember...other then when UPS trashed my 2002 Black Knight in shipping...BowTech overnighted a brand new bow and dealt with all the UPS BS so I wouldn't have to.
Not saying they dont have their probs..but I've had cracked limbs from everyone BUT BowTech

...mathews, hoyt, pse, martin, etc etc...
Sounds to me like a pocket or rocker problem.