Hate to say it but it seems to be the nature of bamboo unless you get some Primo stuff. Maybe it was perfect for your draw length,the way you held the handle, his fingers were fatter than yours???
I had a James Parker, Ipe, Bamboo backed, R/D bow that I shot 200 times, then it lifted a splinter on the top limb. I talked to James and decided to sinew back it.
I super glued the splinter lift, sanded it smooth, then put two courses of sinew. After shooting it about 100 times the ipe fretted just past the handle area. Go figure?? Wrapped it, super glued the wrap, shot it and the other limb did the same thing in the same place.I wrapped it, super glued it, backed it with a water moccasin skin and it shoots 5# heavier and is one of my hunting bows this year.
James told me that if you get boo that is inferior the lams have a lot of problems, no matter what.