"My insurance wasn't good enough," said Lord McWilliams, 20, who has a deadly liver disease.
His brother, David Williams, wanted money "to speed up the process," McWilliams said. "Medicaid only goes so far."
He dismissed as "crazy" federal accusations that Williams was a Jew-hater who wanted to wage jihad.
McWilliams said the FBI informant who lured his brother and three other hapless petty criminals into a plot to blow up synagogues and shoot down a plane promised enough money to take care of his transplant.
"[My brother] told me, 'Don't worry, when you go to the doctor, tell them you got money,'" McWilliams said.
McWilliams, who has already had his spleen removed, said his brother told him he would have $20,000 for the operation.
Their mother, Elizabeth McWilliams, said her older son had told her he would be able to give her a wad of cash Thursday, which was the day after the terrorist plot was to have been carried out.
"He was a loving, sweet kid. He took his brother's illness worse than me," she said.
Lord McWilliams said the informant, who often drove his brother to the hospital to visit, even promised to take him to Universal Studios when he was well again.
"He said I didn't have to pay for nothing," McWilliams said.
Federal prosecutors say Williams, 28; James Cromitie, 44; Laguerre Payen, 27, and Onta Williams, 32, all of upstate Newburgh, were militant Muslims caught on tape railing against Jews and plotting to blow up Jewish temples.
They were arrested last Wednesday while planting what they thought were plastic explosives outside two Riverdale synagogues.
They also had a Stinger missile - phony, supplied by the FBI - with which they allegedly planned to shoot down a military plane. Family and friends say the four were down-on-their luck ex-cons who apparently thought they would be paid by the FBI informant.
In dozens of interviews around Newburgh, no one can remember hearing any of the four talk of Jews or jihad. They had converted to Islam in prison, but they drank beer, ate pork and rarely prayed, family members said
Sad story, and the informant has obviously led them on.
Spend much time with criminals and you'll see that anyone accused of anything has a reason why they're innocent, or why it's someone else's fault.
They still knowningly engaged in a plot to kill innocent people though, even though it looks like they're not textbook Jihadists. And saying you were willing to kill people for money but you have a sick brother does not hold much truck with the courts.
Their lawyer should go for entrapment, but from what I read, the courts have ruled against such a defence in these cases previously.
The stupid and the impressionable can be dangerous.
Richard Reid and that white kid last year in England that blew up the coffee shop were idiots too.