I think they are confusing "conflict of interest" and just "in their interest".
If you asked me if my friend Bob should get a free $100 or if I should get a free $100; of course I'm going to choose myself, as that's in my best interest. There is no conflict though.
I believe the core point being "of course particle physicists want more funding of particle physics"
That's not a conflict of interest, like at all. What are you talking about?