How are you making sure that you're producing product that you feel confident sending to someone who actually knows the relevant area?
Expectations are extremely low when you start. The bar slowly rises year after year, and the day you're unable to exceed them consistently is the day you're pushed out. Success in biglaw is a lot about being ahead of the curve, which is very easy to to as a junior and much more difficult as a fifth year.
That's why it's actually conducive to your reputation to be working hard as a first year. The idea is that even though you don't know much, at least you have the right attitude and are willing to put in the time. That's the only real way you can set yourself apart in the beginning.