No, he is just lagging here is how
when a person has less connectivity the persons movements doesn't reach fast to you, in his case he would see you all paused and he is moving normally, when the connection gets better his position will change to his current position where he is now,
Now link it with your example
When you shot 10 arrows at him he was actually not there, therefore he didn't die when the connectivity got better he was at the flag and he captured
He is not a hacker