The four children of the Queen are meant to be in a single row but it really is hard to maintain perfection. Andrew is not supposed to get in front of the King, but he’s also not supposed to be behind him - it really is to be expected he may do both.
(I am talking about in this situation - in other situations, Andrew is now definitely supposed to walk behind the King - but at this funeral, they are all participating as children of the late sovereign rather than as a King, and a Prince.)
I would be very surprised if he is doing it deliberately - Andrew is a deeply flawed man, but he is actually pretty obsessive on the protocols - that is why he is so distressed at the parts he is no longer permitted to fully observe.
So is the protocol that you are suppose to be behind the King..even Camilla..except when they are marching like this?