The Scottish Law used to be against front shots from Gatsos due to the white flash, but the law was changed in the last few years to allow another flash based detector to catch speeders. Gatsos shots that are coming into the camera flash aren't still allowed if a white based flash, I asked that of a friends traffic cop brother.
Privacy laws were also a reason as to why you couldn't done from the front, but the law was also changed. I got that from a friend in the Tranport dept in The Scottish Executive. Hes a good source of info as I trust him, as know this as I for the Scottish Executive.
Ok the only advice I can give you from others I have seen is to:
1. Its a Court case, dress very smart
2. Plead guilty, no point trying to get around this. Your m8 was nabbed fair and square.
3. Get his lawyer to build a case as to why he shouldn't loss his License due to family, Job and financial commitments.
4. Dont try to get around it as judges take dim view of this, if he shows thats hes sorry and not going to do it again the judge may take this as a one off.
5. Hope he has a clean license to help his case, if he has points or run ins with the law the judge may not be nice in his ban and fine.
Hope this helps m8, but hes got a good chance of getting some length of a ban.