Have I done a bad thing?

On my way into work I noticed that the seat next to mine on the tube had an empty sandwich wrapper on it. Rather than one of the traditional Marks and Sparks plastic efforts, it was a very American-style open wrapper, enabling better access to the food within. It also seemed to contain the remnants of someone's lunch.

At King's Cross, with all other seats taken, I noticed a large-ish man angling for the seat. He was carrying a couple of bags, and quite clearly needed to take a load off. I assumed he'd see the wrapper and discard it, but no, he turned round and slowly lowered himself into the seat, seemingly oblivious to the lunch up his backside.

I stayed quiet, not wishing to be associated with the offending article should blame become an issue.

So I'd seen all this happen, had it within my power to prevent trouser spoilage, and chosen not to.

The question is, would I have done anything different had I failed to notice the bloke heading for arse-sarnie interface was carrying a rucksack emblazoned with the Manchester United shield?