Splinter on yew longbow sapwood.

I have just finished a yew self-bow and have shot it for the first time today. All went well but I have noticed a splinter rising on the sapwood back. The sapwood was quite thin and in places the heartwood comes though in other parts along the back, so the bow looks a bit of patchwork. Is this a result of the sapwood not being continuous and will it keep reoccurring?
Any ideas would be welcome.