I have the same problems with my driveway. Due to having a north facing driveway and driving over the snow, I had several inches of ice in my driveway for over two months and almost a foot of ice in the street in front of my house. I did not use any ice melt except for what may have been on the vehicle tires. Now that the ice is melting, I have discovered additional areas of deterioration. It is most probably due to freeze/thaw, expansion/contraction, etc. I would bet that most of the areas that are "crazing" or "spalling" were pre-existing and now the insured has "heightened awareness."
I should add, to the best of my knowledge, depending upon age and quality of the concrete, certain salt type chemicals can have an adverse effect to concrete. But it is doubtful that a few applications of the product could damage a driveway or sidewalk that wasn't already crazing and spalling prior to this event. As Mike said above, you may want to do some research or contact an expert to determine how the chemical the insured claims he used will effect concrete.
As Steve points out, it appears that this is probably not covered for reasons explained above. It is also probably not a sudden and accidental occurrence.
http://www.madsci.org/posts/archive....Ch.r.html
Gimme a bottle of anything and a glazed donut ... to go! (DLR)