Brilliant...drive the character (sorta Steve Conradish styled), yet move the story.
It felt differing, almost like it belonged on another show, yet it meshed perfectly; hard to get that mix right. And they didn't take the endlessly cheesy "Freaky Friday" (or "Vice Versa", "18 Again!", "Like Father, Like Son") tact about it -- rather more high drama.
Still I think the whole T.J. play was a bit TV melodramatic overdone, I would have opted to just deal with the 'exploring Tom's life' bit, and flesh that out, provide a deeper character slash backstory play. The T.J. kick up is too easy, too instant microwaveable. T.J. only got caught on account of Shawn's 'betrayal', in terms of Nova Group the more rational response is to attempt a rescue, not mount a hit. Sorta felt like a script that was decided on by committee, going in several directions, still they managed to pull it off.
Everyone all doom and gloom with the start of Season 3 and then you watch an Episode like this, all hope remains (imho).