Splicing a bat means getting a small surface area to hold tight despite massive pressure on it, the way it works is that the splice is cut smaller than the handle, the force of the handle in the splice creates added strength to the bond. When it is slightly out for whatever reason the result is a big snap, remember that this is a bond between 2 organic and unpredictable pieces of wood so this will happen, I've had mine go the same way before too.
The alternative is to make the gap the same which will allow for no breaks like this but also gives a weaker handle and results in the masses of cracks along the line of bonding and through the shoulder as is common with many Asian bats. Then you see filler being used and the handle join is inferior for life span and performance wise.
You will be looked after by SAF, just focus on the point that everyone liked it, you can't say that very often with bats.