You're misusing probability and ignoring critical information. There's 1000 red marbles added to a jar with 8000 blue marbles (9000 total). Take three marbles

You're misusing probability and ignoring critical information. There's 1000 red marbles added to a jar with 8000 blue marbles (9000 total). Take three marbles from the jar randomly, one at a time. The odds of getting three red marbles is ~0.14%. That's all. Tor nodes are not randomly picked marbles. The Tor network is not a jar.