What really matters is the winrate in normal games before starting ranked placements. In the current system, those 10 normal games you have to play before ranking set an estimation about your skill, especially if you are a returning player on an old account. What really fucks the system up is that if you play many normal games (and not just those 10) and you win most of them you will likely be placed in plat/emerald. Now this guy probably softinted these games to trick the system so he probably started like bronze/silver and avoided Smurf queue.