They don't need to be in the witness statements. There are a lot of people who have no idea what those words even mean. But just for the purpose of this discussion, I will post the definition of Collusion:
col·lu·sion
/kəˈlo͞oZH(ə)n/
noun: collusion
secret or illegal cooperation or conspiracy, especially in order to cheat or deceive others.
"the NFL Owners were working in collusion with one another to prevent higher contracts among players"
So whether the witnesses knew when they told the reporters that NFL owners working together to prevent players from having higher contracts, especially QBs, after the Watson deal is collusion, that's the literal definition of the word.
If someone says they witnessed someone in a courtroom speak under oath, then told them what they said on the stand was a lie, it doesn't make it not be perjury just because the person didn't use that word when they told the reporter what happened or didn't know what the word meant.
The actions define what happened and whether it was collusion, NOT the words being told to reporters by witnesses.