The incidents involve both urination and defecation. Could the cause still be a UTI?

Scout was treated at JVC. I don’t know the particulars of the UTI results. Tux is fed nothing but canned DM (purchased at JVC). The only variation is if we are out for the day and the time of dosage of the insulin may be delayed as well as the Pro Plan feeding. In consideration of the diabetic needs the DM dry is available to Tux. Since it is more appropriate for Scout to eat the DM than Tux to eat the Pro Plan, Scout will eat the DM. The wet food may be gobbled up by both cats and the next feeding and insulin may be delayed leaving them with nothing in the meanwhile.