invalid argument

"simply quoting a source once does not mean that an organization supports or endorses everything that a source says or does"

No, it doesn't. It does, however, imply that you think the source is reliable, trustworthy, accurate, etc. Otherwise, why would you quote the source even once? Cameron's methods have been discredited by every reputable scientific organization. His conclusions have been disproved by reputable researchers. By quoting him, IFI DOES endorse Cameron. And that is very, very wrong!