I'll have to look that up too cuz I bought an extra side of fries for a Jain friend and then they couldn't eat them and it made them feel bad which then made me feel bad because they were earnestly so sad about wasting food. I did make some killer breakfast burritos out of those fries so not all was wasted but in the moment it was a real bummer. There is a serious lack of fast food options that are veggie/vegan that aren't a salad.
I worked there some time between 2005-15 (I'm old and can't remember years well but it was definitely after 1990) and I absolutely was told to put the lard in the fry vats. Interestingly they used canola oil for the non French fry vats.