My guess would be that a team leader would need to seek the opinion of someone higher up simply when they don't have the authority to make a decision.
Everyone should be encouraged to take on responsibility and show initiative - but it's equally important to know your workplace limitations.
Otherwise, you run the risk of making the wrong decision - which could have potentially serious consequences (depending on what you're making a call on).
Team leaders need to seek senior authority sometimes
There's no shame in asking for advice or a second opinion when you need one. A great example would be a diligent doctor.
Although it's a career that requires a lot of ambition and confidence, the career path has strict boundaries and limited jurisdictions for each role.
Junior doctors always seek the opinion of more senior staff when they're unsure - and because the cost of failure could literally be death - this kind of workplace requires strict adherence to the chain of command.
Perhaps this is less so in other work places.
Nevertheless, over-stepping the mark of where your authority ends could irritate those around you, making for a very negative work environment - regardless of its nature!