Farming Villagers sometimes plant on dirt

As I built a farm in the desert to allow the farmer in the village allow to work (farm wasn't generated) he managed to plant a crop on a dirt block that was hoe'd before some seconds ago, which then has been trampled to normal afterwards.

I wasn't able to harvest it after growth as it something destroyed when i wasn't watching (block-update maybe?), I can just confirm it was actually there and dropped a seed on destruction