if the wood was green and not entirely dried out, the splitting will occur with any wood. Your post and post post sounds like this is pine and could be a knot that did not and will not absorb any product and it could have been leaching tanin that would repel the conditioner while covered. The splitting issue can be solved possibly by wood filer, inset screws to pull the wood back together, or injection with an adheasive and clamp back together, or removing the split piece and making a template and making a new piece with better wood.
But, green wood or un properly dried wood will do this when left to finish out drying. The Flood product did not cause this to occur, it would have nourished the wood and assisted in preventing this from occuring.