Sounds odd, I have never heard of having to itemise floor coverings separately on an insurance policy!!! Is he just not covered for contents full stop? Or no cover for floor coverings? Don't forget there are two parts to home insurance, contents and building
TBH with an escape of water, balls to the contents - sorting the fabric of the building is the most crucial thing. the insurance company is responsible for this.
I would advise your mate to phone them back up and tell them he isn't taking any s**t and wants someone sent round to take damp readings. His excess would probably cost the same as going and hiring a dehumidifier for a week, but getting a proper restoration company in will ensure the problem is sorted and he isn't going have a problem with dry rot in 6-12 months time. If that happens, it will again be the responsibility of the insurance company and there may be a case for some sort of legal claim due to their negligence in dealing with the initial problem.