Crow's definitely going to try to be sneaky about hiding the fact that he's not eating the food he tampered with xD
I could see that too. During the day of the interrogation, he's going to be exhausted from staying up for a good portion of the night to run around doing Jaxon's bidding. Gavin might catch onto that too.
I think the plan was for him to go alone the first time and then try to convince everyone else that something's up when he realizes Crow is working for Jaxon. When that doesn't work, he pesters Penelope to follow Crow with him a second time later on. That's when she would learn that Gavin was right all along (or so it would seem ;3)

If we want to change anything, I'm open to other ideas though. We don't have to stick to the first plan if you've got anything better