Here's an alternative, more likely take regarding Eric Gonzalez in the death of Jordan Neely -- he was telling the truth then, and he's lying now.
Gonzalez's story on the scene was that Neely tried to hit him, and that's why Daniel Penny took Neely down in a chokehold. Gonzalez is the man seen holding Neely's arms while Penny had Neely in the hold. Gonzalez said, at the time, that after the police had arrived, and he and Penny released Neely, that he asked Neely that he was okay, and that Neely said, "Yeah." This works with the police report that showed that Neely was alive well after being released by Penny and Gonzalez.
Why would Gonzalez lie now? Well, it's because Alvin Bragg is a racist, corrupt, and unscrupulous DA who has no case against Penny. So, Bragg made a deal with Gonzalez -- Gonzalez receives immunity in exchange for testimony that he apparently was the only person on the train who didn't see Neely going nuts, and that he wasn't sure that Neely was still alive when he left.
Why is that important for Gonzalez? Well, Penny is facing felony charges. If Penny is convicted, and Gonzalez didn't have immunity granted by the DA, he's an accessory to whatever Penny gets convicted of.