OK, so you could tell it to display 8, but only segments e and g, and that would display r?
Stop Thief's segment decoder has different patterns for several digits- 6 and 9 don't have the "tail" segment (a for 6 and d for 9), and 1 is scooted to the left, using segments e and f instead of b and c. It also has a C (adef), d (abcdg), F (aefg), G (acdef), and t (defg). The game also displays - and r which aren't in the segment decoder.
I uploaded ROM dumps for TI Programmer and Business Analyst I, and updated the pinout files and output PLA info. I need to clean the output PLA of TI Programmer to transcribe it, although I think we know enough to reconstruct it if need be. Along with 0-9, it displays A b C d E and F.