Was he egged or not ?
So the intention was enough?
Thought police next
Yes, intention is enough. That has been the case for centuries. Nothing to do with “thought police”.
There are two components of an offence - the act, and the intention to commit it. Generally, you need both to be found guilty.
So if you are carrying a gun and you intentionally shoot it at someone, you will be guilty of murder. The act here = firing the gun, and the intention = meaning to shoot at the person.
The same analysis is true if you intend to shoot at the person and miss, or you only wound them. You intended to fire the gun, and intended to shoot the person. But because you didn’t actually kill them, it will be attempted murder rather than murder.
If the gun discharges by accident and kills someone, you are not guilty of murder because you committed the necessary act act but lacked the necessary intention. You will probably be guilty of manslaughter for carelessly killing someone, though.
If you just have the gun, and think about shooting the person but do nothing - you are not guilty of anything (that’s your “thought crime” example).
In this case the protester clearly intended to throw something at Charles and did throw something at Charles. So clearly they have both elements needed to have committed a crime. (The fact that the egg didn’t contact him is irrelevant in this example, because the offence doesn’t require it)