That just means his first 3 picks were taken before he got his first or second pick in. If you noticed, he still was unlucky since you took his first pick from him. He ended up with 3 and 4 while you got 1 and 3.
How it works is that you get your highest available pick and then it moves onto the next player in a snake format (just like how attack turns go). So if you got the 5th pick and the other guy's 4th selection was the same as your 1st and his first 3 picks were already taken by the other 3 then he would get his 4th (and your 1st) despite your having it higher ranked. You still likely benefit as you end up with your second and third pick while he gets stuck with 4th and 5th.