From what I've been told by a couple of building inspectors, if asbestos was disturbed and dispersed in an enclosed area in the past, it's not even safe to spend any time in there, nevermind go back in and further disturb the stuff. All of that incompetently moved asbestos is still up there, on the rafters, in the floorboards, in the dust ready to be kicked up into the air and tracked down into your home. The danger is more the abestos you don't see than it is the chunks that are still visible.
Not sure how much of that is scare tactic but that's what I was told more than once when I was buying my house and seeking advice because it has old asbestos shingles underneath the vinyl siding.