champ select....

This has confused the hell out of me. how come when i get a day that im lagging for no reason (happens to all of us), i call the role that i want, and someone, who apperently got the role before i even joined in lobby, never says anything about it? it happens to me ALL TO OFTEN. Now, this is in blind pick, of course. i want to jungle. i call it. but apperently this person already called it. at the last second, he says, "oh yea and im jg" CAN YOU SAY SOMETHING BEFORE HAND?!?!?!?!?!?!? like, i know that he probably got it before me. i dont have the fastest cpu on the market, but people who get the role before someone who called it, and joined late, are just, excuse my language, ASSHOLES. I dont mean to offend, but can someone explain to me the thought process of someone who does this? i had to go Top lane Irelia because this kid didnt want to give up jungle, to a person who had no knowledge of him even calling the lane. we lost the game because of me, which i understand. but to me, at least say that you got the role before the last 5 seconds. Thank you for reading.

-Volvalgia