Acts 10:
10:9
On the morrow, as they went on their journey, and drew nigh unto the city, Peter went up upon the housetop to pray about the sixth hour:
10:10
And he became very hungry, and would have eaten: but while they made ready, he fell into a trance,
10:11
And saw heaven opened, and a certain vessel descending upon him, as it had been a great sheet knit at the four corners, and let down to the earth:
10:12
Wherein were all manner of fourfooted beasts of the earth, and wild beasts, and creeping things, and fowls of the air.
10:13
And there came a voice to him, Rise, Peter; kill, and eat.
10:14
But Peter said, Not so, Lord; for I have never eaten any thing that is common or unclean.
10:15
And the voice spake unto him again the second time, What God hath cleansed, that call not thou common.
10:16
This was done thrice: and the vessel was received up again into heaven.
So, see, God told Peter in a vision that it was OK. Really.
I don’t know of the story in question, but there are two things that may be at work here. (1) In Buddhism, Life is Suffering, so it’s considered good in Buddhism to inflict the least suffering on other living creatures, and hence it’s a good idea to eat as far down the chain of being as you can (i.e., better to eat beans, which have little sentience and suffer little than, to eat a cow or pig). (2) Buddhist monks have historically begged for their food, and, since they live on the sheer good will of others, it would be unthinkably rude to not eat whatever is put into your alms bowl. Hence, if someone gave a devout monk some rotten meat, he would be required to eat it.
Probably. It probably wasn’t Siddharta Gautama, THE Buddha. Lots and lots of other Buddhas out there, though.