Dang, that's right..
Theft is taking those steaks from where RPM put em and out of the store without paying for them. So wouldn't a continuous recording of those very steaks from their arrival on the shelves, into his pants, and from there straight out the store past the registers be proof enough?
All there'd need to be is enough cross-reference to validate the recording's continuity. All he has to do is walk past the registers once for it to be theft.
If the video surveillance was airtight, it would probably be possible to keep a tally of steaks substracted from the shelves versus those paid for at the cashiers'. Barring any other thefts, those steaks would be the only ones AWOL.