Several landmark claims went through the courts this week, leading to fears of a spiralling compensation culture and large rate rises.
The judgments were made as the Institute of Actuaries revealed compensation culture was costing the UK £10bn a year, with a third going on legal and administrative costs.
Rugby player Richard Vowles sued rugby club Llanharen and a referee, represented by the Welsh Rugby Union, after a scrum left him tetraplegic. Llanharan was insured by Norwich Union and the Welsh Rugby Union by St Paul.
Vowles was successful against WRU and was likely to be awarded £1m.
Hugh James partner Gareth Williams said this meant "insurers are likely to feel real nervousness when insuring sports governing bodies and individual referees".
WRU has requested permission to appeal.
In a win for insurers, golfer Andrew Rait lost his claim for £6.2m after the High Court found a dog bite did not affect his golf career. Rait said the bite to his little finger ruined his chances of making the Ryder Cup team and sued the dog owner.
Keoghs' sports law unit head Gareth Williams called in experts to demonstrate this was not the case and Rait won less than £5,000.
Williams said a successful outcome could have opened the floodgates for loss of earnings sports claims.
Meanwhile, real estate agents fear increased professional indemnity premiums after one was sued by a vendor for breach of contract.
Michael-John Knatchbull sued John D Wood & Co after his London house sold for £1.5m but a similar house close by sold for £1.8m.
The High Court found Wood was in breach of contract for failing to tell Knatchbull of the higher priced house.
National Association of Estate Agents (NAEA) chief executive Hugh Dunsmore-Hardy said the decision was a "travesty" that would have a serious knock-on effect on agents' premiums.