The next thing on my list

I used to be a project manager at on premises software installations. There was this 1 guy on my team who had a problem with me being in charge if the team. I'm not sure why, perhaps because we were the same age, or perhaps he just felt superior and was frustrated that his job title didn't align with that. Whenever I asked him to do something, he would respond with "That's the next thing on my list." Always. Whatever I came up with, whatever i wanted to make sure he wouldn't forget to do, it was the 'next thing on his list'. What he was really saying was "you are not telling me anything new, I am way ahead of you." And I knew he was lying. But I had no proof. Until I figured out how to catch him out in his lie:

So one day, I decided to trick him and ask him: "What is the next thing on your list?" He told me what he was planning in doing and then I said: "Okay, and don't forget to install the updates after that." He followed up with: "That was the thing after my next thing."

Grrrrr 😡😡😡😡