I'm not surprised the lad got overloaded. You're so excited during the early solos that your comfort zone is very small - anything different can have strange consequences. I remember on my first cross-country getting into a muddle with an RAF controller (I couldn't understand him at all, first time it had ever happened) who was clearly working hard and talking very quickly. After passing 500ft I contacted him and it took me two attempts to hear the digits he wanted for the squawk.
It hardly rattled me, but the result was I left full power on in the cruise after trimming the aircraft, and hadn't noticed until I heard the same controller advising a crossing a/c of my presence with his tone suggesting some surprise at my airspeed....I was very surprised I hadn't even noticed.