When building a generator, or choosing research options as the joined person in co op if you choose the middle choice it correctly reflects it, but if you choose left or right; for example If I choose science as my generator, the game will build a food one by mistake. When you purchase items at the vendor this is more noticeable as the item you pick to buy will not be the one dropping.

We have tested this and it only happens as the joined person in a co op game