Frankly, if solicitors behaved like some claims assessors they would have been struck off ages ago. Solicitors provided a good quality service, albeit usually funded by legal aid. Now there is a free market. Solicitors still have to conform to professional rules of conduct. Claims assessors do not.
Some assessors are simply crooks.
Recent cases have involved phantom passengers in car accidents, and even almost a whole street who allegedly were on the same bus involved in an accident. Claims are ratcheted up to include injuries and loss that simply never happened. Minor bumps that would cost a few pounds to repair become total write-offs. The government does not seem concerned, as legal aid is not funding this sort of activity. However, everyone pays by way of increased insurance premiums.