I've had 2 narrow, 1" or less wide, Hickory backed bows blow up on me in the past couple of months. Both of them went at much smaller knots than yours. I even left a little extra wood on the edges in attempt to compensate for the pin knot. They still blew. The second one blew when I was stringing at first full brace height. Shards just missed my right eye, grazing my cheek.The main part of the same bow whacked me in the chin, splitting it open. Probably could've done with a few stitches, nice scar now. Heck I was too pretty before anyway.
Using clean straight hickory is virtually bulletproof, so I'm not going to use anything less than that from now on.
Hamish.