Not starting 182

[mb0809]

My 182 was running fine but other day the car cut out while driving and now will not start, it turns over and you can hear it pop through exhaust, RAC seem to think it was timing belt or timing problem, taken to a garage who seem to think exhaust valves have burnt out and that timing belt is ok, would the valve issue cause it not to start and if it is this could more damage have been done

thanks