I believe it was Roux who stated the 20, I'll have to confirm that, either way if the measurements were 1.1 to 1.55, that's more than 20. Just like Roux tried to tell Dr. Stipp that his call to security was at 3:27 and not 3:15:51 or thereabouts. Just more defense tricks imo.
http://www.enca.com/south-africa/oscar-trial-day-5-kicks-doc-who-tried-save-reeva
Dixon said repeatedly today the height difference was 20 cm
Roux is an old sneaky vampire, overrated and overpaid, should get cast as the next count dracula