Well if the person didn't KNOW that it was putrid. It doesn't matter if it's not part of your diet, the buddhist monks are all vegetarians - but if someone comes along and gives them meat, they have to eat it.. AND be grateful.
It's not RUDE to give someone food! Wanting a specific type of food is greedy and selfish and that's the type of behavior that makes the cycle continue.

If a person offers you food, even if it's something you don't like or if it's putrid but they don't know it - that would give them good karma, and you can't deny the person that good karma since all our karma is a collective thing and we all need to work to improve it. We're greedy and selfish because we're tainted by bad karma.

Siddharta Gautama died because he ate rotten meat btw. Vegetarians will claim it was a mushroom, but it was meat. :P
He also did a whole lot of other selfless things like that. For example, when he was an elephant - he helped a hunter saw off his tusks. He also gave away his family to a stranger because the stranger asked him to.

You can only achieve good karma, and thus perfect compassion, by killing your own ego and realizing that there is no "you". His stories sound insane, but that's what it takes.
Good karma is not about doing good because you don't MIND, like giving a homeless person your change. Good karma is, if that homeless person asked for your house, your clothes, your money, your car, and everything else - you would give it to him without even thinking about it, and you wouldn't regret it nor feel good about it. And you wouldn't do it -because- you wanted good karma or -because- you wanted to do good; you'd do it just... just because. Because he asked.

That's a scary thought for many westerners and that's why the west invented its own version of reincarnation and karma which is, ironically, based on ego, greed, desire, stupidity and me me me me me.