Even wounded the intruder was able to out run the old folks but think about this...why did the couple chase after him? The intruder no longer posed a threat to them.
Because not everybody stays 100% rational "in the moment" and some of us are by personality (or having been raised in Brooklyn
) under stress subject to unwise reactions like "that sucker has my handbag!" (or "who does that young whippersnapper think he is?") which may not be sensible but there you have it...on a rational and legal basis I agree this was foolish but...we are human and yeah I'm guessing they wanted her handbags on principle.