Had a similar incident myself this week but thankfully, the other driver stopped before collision. However, I would deem this as undue care and attention when at speed on a round-a-bout by third party driver.
Hope you got all the details of other driver and informed your insurer whether you have to claim or not. Get at least three estimates for repairs and inform the third party either direct or through your insurers to see if they will pay your repair bill.
Good Luck!