I'll be honest I don't watch enough boxing nor understand the technicalities of the sport well enough to guess what went wrong.
The only things I really noticed was
1. Jake was able to spot Tre was a right handed boxer.
2. He managed to avoid being hit with the left handed strike
3. He moved in on Tre with a surprise upper cut when Tre advanced (I'm guessing this was the error here, though I can only say that from what I've learned about Fencing, which is that you have to capture the position before striking, otherwise you leave yourself open to a faster attack.)
Though I was a little confused about the movements, as Tre's left handed attack wasn't actually successful in either of its two objectives, so I don't fully understand why he would have still moved forward as Rilla described it. (Which he described as taking place if the attack was successful, as far as I can tell.)
I'll be happy to see what people who understand boxing can come up with.