Several designs have 'break away' stitching where the attachment strap is sewn over itself again and again that helps to stop you a bit slower than if you were on a regular tether. It would be no good to reuse. Besides that, I have know a couple people that have had the displeasure of testing their harnesses in actual falls. They said it tore the he** out of their legs, shoulders, and belly where the straps are. It's like my airbag and seat belt...I will just assume that they are going to work instead of testing them out!
rw