Theres no way to know exactly what went wrong with that drop. When I work for my Uncle droppin trees, if there is ever a doubt in anyones mind something might not drop right, it gets climbed, a rope gets tied, or we get someone in there thats more skilled and experienced to do the job(a better climber than me). If I'd dropped a tree through someones house like that, I don't know how I'd live with myself, especially when its the home owner or a bystander that gets hurt, groundies and other workers know what they are getting themselves into.