Cooked potatoes with sprouts

I disgree -- the problem with sprouted potatoes is that the sprouts themselves (as well as parts of potatoes that have gone green) have higher concentrations of glycoalkaloids, which are moderately toxic. I suspect if your dad forgot to remove the sprouts that means they were tiny and therefore probably unlikely to contribute enough glycoalkaloids to cause harm, but this would be your judgement call. This article has more to say:
https://www.chowhound.com/food-news/54631/are-sprouted-potatoes-poisonous/

The potatoes should be fine as long as they weren’t soft or shriveled up.