in the "hot hand" phenomenom.

I can't speak about baseball, but in basketball hitting streaks exists.
I don't know exactly what your professor or the sad-ass intern studied, but I believe they mistaken because they simply can't estimate all factors (nobody can). And very likely they replaced a reason with a consequence.

Even simply hit rate is different for various players.
It can't be said that better players have more/longer hitting streaks because their average hit rate is higher. In reality, their average hit rate is higher because they have those hitting streaks

Also, when a player and his team feels that he is "hot handed" in a certain game he takes more chances. Trying hard shots, leads the game, etc. Under "normal" circumstances he wouldn't even try to throw from the center but being "hot handed" he may try.
Keep in mind, that 1 basket out of 2 is easier than 10 out of 20 because defenders (as you also noticed) will pay additional attention to you and, in general, it is harder to create 20 shot-attempt situations for yourself than just two. In practice, that means you will take more risks and shoot from not-so-good-positions more often.