the response was a combination of impotent sputtering and backpedaling

https://www.npr.org/sections/goatsandsoda/2021/11/11/1052719247/how-6-billion-from-elon-musk-could-feed-millions-on-the-brink-of-famine

Literally an NPR article on the subject, outlining how that sum could solve world hunger.

In response to Musk's request for details, Beasley (head of the World Food Program) tweeted him the math: "$.43 x 42,000,000 x 365 days = $6.6 billion."

That's how much it would cost to provide one meal a day for one year to this population in need, says WFP. The agency would deliver this "meal" in the form of food aid, cash or vouchers.

The food aid, says WFP, consists of commodities such as rice, maize and high-energy biscuits.

Then Musk claimed to have donated $5.7B several weeks later. However, this money was not directed to the WFP

Musk estimated in December that he would pay “over $11 billion” in 2021 taxes. A large donation could help to offset that price tag.

So it looks like Musk was looking for a large tax write-off, not a cure-all for world hunger. And when he found a viable place to dump his money, he took it. This wasn't about food aid at all. It was about Musk figuring out what he could buy for the price of a tax cut.