Has anyone else had this happen?

My farmer is now a master healer after only 1 real-life hour playing a new village. She wasn't the one checking out the herbs either, and started with no healing skill. My builder got sick so I had her heal him (her first time healing anyone) and it told me that 'the villager has already mastered this skill' so I looked, and sure enough!

Would this be considered an event? Or just a glitch?