LO - not sure I agree that "I'm not aware of any differences" doesn't count.
If you believe this then what you are in effect saying is that Simon isn't aware if there are differences. I find this hard to believe for someone in his position and it doesn't seem credible that he would not know about these things.
Conversely, if he is aware of some differences then by saying "I'm not aware of any differences" he would in effect be lying to the Defence Committee - I see no reason for him to do this as it would be an enormous and unnessary risk on his part, as team records will prove his knowledge of such variations and could land him in a lot of trouble. All he need say if there were differences is that there are slight variations but the UK model still meets UK requirements. Who would care? LO is overated anyway.