One game does NOT show a persons skill.
Something I see a lot in game that I'm getting sick of. That 0/4 bot lane is not a shit player who bot their account. You beating someone a higher ranked than you once does not mean you deserve that rank. You going 10/2/0 in a game does not make you a god and better than everyone on your team. Games are random, shit happens. I've had games where I go 12/0 and carry, I've beaten diamond players as a gold player, I've lost to bronze / silver players, I've gone 0/6 in lane phase. Shit happens. What decides how good of a player you are is your actual rank or mmr. How well you do as an individual over multiple games and how well you work with a team.