I'm Assuming his Twitter is private right now, but his Mastodon does share the same event (minus the "nuclear"): https://hachyderm.io/@robpike/115782101216369455
And a screenshot just in case (archiving Mastodon seems tricky) : https://imgur.com/a/9tmo384
Seems the event was true, if nothing else.
EDIT: alternative screenshot: https://ibb.co/xS6Jw6D3
Apologies for not having a proper archive. I'm not at a computer and I wasn't able to archive the page through my phone. Not sure if that's my issue or Mastodon's
Don't use imgur, it blocks half of the Internet.