The moment was just a flash, but it was immortalized by Neil Leifer:

“Luck in sports photography is everything, but what separates the really top sports photographer from the ordinary is that when they get lucky, they don’t miss.” https://twitter.com/MatthewAguilar5/status/1265049948871184385

The photographer between Ali's legs is Herb Scharfman, an older rival of Leifer's at SI. He picked his spot by the scorer's table for better maneuvering, leaving Leifer on the other side. Worked out for Leifer!
The stunned guy over Scharfman's shoulder? A young Larry Merchant.

A pair of notable baseball photos snapped by Scharfman: Roger Maris's 61st home run, and Curt Flood making a leaping catch into the ivy at Wrigley Field (SI cover in August 1968)

As for Leifer, here are some of his great baseball shots https://neilleifer.com/gallery/baseball/