EDIT: Ah, didn't see your reply until after I posted this.

He tweeted at Fraunhoefer:

Twitter is super slow on Android. What have you done to fix that?

Which sounds a lot like an attack to me, coming from someone in Elon's position. If you need further explanation, he addressed it at him with the word 'you'.

Also, firing the guy after this exchange is kind of a personal attack.