I mean come on, it isn't difficult. BUY WHAT IS ON THE LIST. Dont go "off piste" and make decisions and then buy differently.
Yes, IABU. However, I spend ages meal planning and he buys something different so I have to rejig the plans.
Annoys me inexplicably. 
And Don't tell me I should be grateful and do the shopping myself. I do, on many occasions. He likes to do it too to escape from the DCs