Indeed, community manager (call that evangelist if you want to) is a weird job. You're supposed to be social, natural - to be as you would be in private life. In cases like these, you're even supposed to use your own identity to support the brand : you are someone real, that get in touch with real people in the most friendly fashion.
But you can't be yourself too much. That's a problem here, since you don't have any other "real" identity. You have to be the brand and as such, everything you do and say is backed up by the brand.
Adria used her own personal twitter account to make her statement, that sounds legitimate. But developer has been fired because she had the weight of sendgrid brand.
That's something very pervert in the community manager / evangelist job : you sell your social self (something I guess politicians know well).
On a side note, I'm quite surprised this can happen in the US, which places free speech as the one and most important right. Not when related to business.