There are a 2 different ways that this guy could have created his simulation without talking to Zimmerman at all: the police report and Zimmerman's retelling of the incident on Sean Hannity's show.
So there is no way the prosecution can claim any right to question Zimmerman based off the re-enactment.
And all of my legal expertise comes from watching every episode of LA Law, The Practice and Boston Legal.
Both of Zimmerman's account though.