Don,
I just got back from a Fiber Training course and I had the opportunity to ask the instructor about this situation. If the cable was designed for underground it should have been OK. Specs would be generally loose tube design, like you said, and gel filled. The gel serves to keep out water. Could it have been old cable? (maybe gel dried out?)
Or perhaps other cables would have greater crush resistance. Some cables could also have some empty tubes in them that might help absorb some crushing force.
Bill
