I had a job where this happened to me and I just let whatever I was currently working on be derailed and worked on that instead. If someone followed up and ask

I had a job where this happened to me and I just let whatever I was currently working on be derailed and worked on that instead. If someone followed up and asked about something else, I would say "X told me to do this." They eventually sorted it out without involving me as they then blamed the other person for the delay.