I think the applicability of this really depends on the circumstances.

• if I see someone stealing basic necessities (people in need steal basic food items, not caviar and £300 bottles of champagne), then sure, I didn't see anything.
• if I see someone waltz into a small mom and pop store and swipe a whole shelf of expensive shit, then that's a different story. I don't give a damn that it's only a few bottles of whiskey, mate, you're clearly not stealing food because you're in need
• and if I see someone stealing a truckload of food going to a food bank, you can bet your tushie there will be fists flying...