is this too legnthy In the case of Roger v Whitaker(1992) 175 CLR 479, the application of the Bolam principle, often used to determine medical negligence in the United Kingdom, could have potentially led to a judgement that the doctor was not negligent
Your sentence is not too lengthy. However, it can be rephrased for clarity:
In the case of Roger v Whitaker (1992) 175 CLR 479, the application of the Bolam principle, which is commonly used in the United Kingdom to assess medical negligence, had the potential to result in a judgment of non-negligence for the doctor.