"I don't think what Max was trying to do would have worked," Vettel said. "Obviously he didn't allow Kimi to move into the inside, and that prevented both of them from clearing Turn One in a normal way. We all three touched and collided, and this was bad news for Kimi and for me. Of course, with hindsight, I would have given more room to the inside, but you want to make the corner and try to race, and I gave room to Kimi, but not to three cars.
So he's basically saying somebody taking the inside of a corner is a hindrance to someone else alongside on the outside. Isn't that just about always the case when overtaking someone in a corner? I still don't feel this unjustifies Verstappen's move.
The only thing I feel Vettel has more or less a bit of a case about is this:
The cars ahead have priority, and this is something he needs to understand. In that regard there was no way he could have made the corner without making contact.
That is somewhat as this is a norm in racing. However, a lot of drivers fail to do so and there's no ruling about this in F1. This norm is in a grey area whether or not you should abide to it.