I'm not quite sure what you want to achieve here. The fact they're Prems means they probably had their ID checked somewhere private to avoid cases like this where people pay excessive amounts of attention to them because they're Prems. This is why VIPs are often checked in in private rooms and escorted directly to the aircraft. The fact that you know they are Prems suggests you were paying a lot of attention and that you were probably just a bit annoyed because as a GGL group 0 you were keen to be first and someone else got on the plane before you.