Unexplained Phenomenon: Why would a booster / cheater change their summoner name?

So, it's been rare that I am 100% certain someone is cheating in game, but it happens, now I've noticed something kind of weird, and I'm at a lost to explain it.

So on three separate occasions I've offered the troll scripter / booster / cheater an 'out' ...basically telling them what I suspect in all chat that if they take the win then I will follow up with ticket, reprots, and screenshots, and take matters all the way to the top, but if they take the honorable way out, I'll forget it happened and move on with my life.

(note #1: no i'm actually too lazy to do this anymore, since while it will make me feel better, it doesn't solve the unerlying issues, which RIOT GAMES needs TO FIX, not individual summoners)

(note #2: this is against the summoners code, and you shouldn't follow my bad example, since you might get reported yourself, especially u people with the limited vocabularies.)

Three separate time I've immediately gone to 'stalk' the user from afar, watching their matches immediately after my own, and looking at their graphs, just to please myself that suspicious looking activity goes largely unpunished and unidentified.

On these occasions, the summoner in question has immediately applied for a summoner name change. It creates a weird situation whereby you have the same match, showing completely different summoner name due to caching update frequency etc.

TL;DR Why would an elo booster, getting caught cheating, change the summoner name of an account? There is a League identifier number which remains constant. Does this fool Riot Support? I mean there must a reason they think this does something? no?