Kent, those are some heavy logs you used!
DD, I suspect the biggest problem from splitting would be loss of (short) nails holding decking, etc on rather than a serious structural failure. My experience with hedge posts agrees with a noticeable incidence of splits, but they do not seem to get long or deep enough to be a major structural problem. I just have to replace some fence staples (2" at their longest). I have not had long (5" and longer) case hardened nails used for attaching 2"x6" cross pieces come out.