Chainguard most likely interpreted Calif's dancing anime girl video as a script kiddie who had found a POC.
It sounds like there was no "co-ordination" behind any of this co-ordinated disclosure. You'd have expected there to be an IRC channel, a mailing list, a Slack chat, or something for something of this scale.
Was there even an incident co-ordinator here? Was any of the parties talking to each other?
And then decided to not ask the PHP foundation about it?
Can you blame them? Calif's unbelievably unprofessional video's leak definitely spikes the cortisol of any actual professional.