Well, I was eventually fired from that job because I wasn't consciously aware of that effect at the time, and was basically unmanaged so neither side acted to correct the issue until it was too late. I learned a lot from that experience after the fact.
But in a situation where one person is the experienced team leader and the other is a junior developer, possibly fresh out of college, I think the onus is on the team leader to ask if they need help rather than expecting everyone to speak up on their own. Maybe the junior doesn't realize they need help. Maybe they're too busy with trying to progress on the code, possibly affected by personal problems, to think about their process.
A lot of the improvements that have made a difference for me as a developer and an employee in general have been learning how to work and manage both myself and the people around me, not learning more about a language or framework. I think that's a big part of a manager's job.