This one is kind of tough. I'd like to think that I'd be better than the Zenefits CEO, but, man, this kid makes it really hard to take his side.
First, it shows really poor judgment on the part of the junior engineer. Dear God, did you think that people can't identify you, specifically? It's not like Zenefits is giving out 10 job offers a day.
Second, you're likely to jump as soon as you get the chance. Neither employer nor employee have any commitment to one another. Okay, fine. But, as an employer, will you completely leave me hanging at a critical time or will you stick a couple of months to complete your task before jumping. Given your lack of discretion, probably you'll leave me hanging.
Third, are you going to air dirty laundry in public? Every company has some, even successful ones. Startups are worse. Again, lack of discretion.
So, yeah, I'd rescind that offer very fast. He'll be lucky if Uber doesn't rescind his offer. I guarantee if I were HR at Uber I'd be trying to pick him out to rescind it.
Would I air that publicly? Probably not.
However, this kid should consider himself lucky that the CEO called him out publicly so he knows what he did wrong. If I were the CEO, I'd probably just rescind his offer without comment. I'd call Uber HR, and they'd rescind his offer without comment.
And, he'd be wondering what the hell happened.