Most PPL's will "infringe" from time to time, either laterally or vertically, albeit mostly inadvertently !
A few weeks ago I was flying down the "Low Level Route" between Manchester and Liverpool zones, squawking 7366 mode Charlie and listening on 118.57. Inbound traffic to Manchester was landing on 05R, so final approach was relatively close to the LLR. Near Northwich I heard a female voice saying: "Aircraft in the LLR, southbound near Northwich, squawking 7366, please identify yourself".
"Oh !!!!!, that's me" and replied with the call sign. Her radar was showing us as about 120 feet above the LLR limit of 1250' QNH ! We descended very rapidly, apologised profusely, and heard no more about it ! Just a simple case of enjoying the view and not paying enough attention to detail !