I tried to locate that quote through my own searches, but only found it on evo-fan sites and this nutcase animal-rights site. If you like associating with the PETA crowd, watch out where they throw the blood.
Leads me to think that either he didn't say it, or that it was a throwaway remark that had no meaning in this context. I'm happy to hear if there's some independent verificiation that this remark had anything to do with his choice of heart. Pigs had already had some success--I don't know why he wouldn't have used a chimp if there was some reason to use it other than an evo-kook thinks it's a better choice...? A close relative on the family tree is not always the best choice for a transplant--not even between humans!
At any rate, I'm not much interested in defending this surgeon's overreach that happened over twenty years ago--a lifetime in terms of the gains in medical knowledge. He entered into an ethical no-chimp's-land with this Hail Mary's pass. I'm pretty certain he didn't expect Fae to live very long as much as he wanted very much to learn something that would save the next baby.
Do the evos hate Seventh-Day Adventists, too? Is there something in their theology that approves of baboons and doesn't care for chimpanzees?