I don't think it was a sealant problem. Something more likely held the case apart. I guess one possibility is that the case was assembled and not immediately torqued togather letting the sealant dry thick, in any case there should be no way for the sealant itself the be the cause of the problem.
I agree with the slow restoration guy about checking case halves. Any sealant that covers up improperly mated cases is no bargain it just permits a more expensive failure later.