Personally, find this a little more interesting, and far more likely:
Tottenham also inserted a sell-on clause when they sold Defoe, which entitled them to a percentage of any future transfer fee. Given the sums involved, that would have amounted to £4m. But Portsmouth negotiated that figure into the final package while the monies that they already owed to Tottenham in instalments on previous transfers were factored in as well.
Portsmouth were due this month to pay the balance on Defoe's transfer to them, a figure of £4.5m, while they also owed £5m on the switch that Younes Kaboul made last summer and £2m on Pedro Mendes' transfer in January 2006.
Little money has actually changed hands on Defoe's return to White Hart Lane but Portsmouth sources are satisfied they have made a £6m profit on him in just under a year. They also received £5m from Tottenham in compensation when Redknapp traded places.
Spurs are stupid, but not stupid enough to parade him before a game. And Pompey are broke and need the cash. It's done.