I have been lucky enough to have been sent first solo twice;
My flying club at the time bought the very first Cessna 152 which was imported to Canada. It sat out front for a couple of weeks, while import paperwork was completed. Everyone wanted to fly this new version of the venerable 150. I went for my lesson on a miserable rainy, gusty day. I asked my instructor if we could fly the new 152 (I figured how can it hurt to ask?). He was the senior instructor there, so I had a better chance with him of getting the 152. "Sure, why not...". I was delighted.
I flew my hour of circuits, as the weather became even less welcoming. He directed me to stop, and as he hopped out, he sternly looked at me and said: "Take it for one circuit.". By coincidence, my mum was in the club house that day, and told me later that the Chief Flying Instructor told off my instructor for sending me solo in their brand new pride of the fleet. The plane had 33 hours total time since new then. The club sold it decades later with 14,500 hours on it, and it still flies privately today.
I also was sent first solo in the helicopter, though that was much more a preplanned event. I think I like the surprise way better!