I think part of the thinking behind the CTC site, is that there is a record of the hole, independent of the council. If you had an accident involving a pothole, and you could then point to the CTC sites data, then the council could potentially be found negligent in not repairing it, and hence liable.
Obviously it would be no good saying; "Look I reported this yesterday and it hasn't been dealt with yet", but so long as the council has had a reasonable time to deal with it, the there could be a case to answer. I would also guess how fast they should rectify a problem may also depend on the severity of the hole.
IANAL, YMMV, yada yada...