As most of us know, the tripped position of a circuit breaker is
different than the Off position. The tripped position is kind of mid-way
between Off and On. We then need to turn the breaker Off and then On to
reset it. As far as I know, there is no way for the user to manually set
a breaker to the tripped position. The only options a user has is On or Off.

So let's assume we have this (common?) situation:

2 adjacent single pole breakers are tied together with the appropriate
tie bar based on the breaker's manufacturer. This is done to ensure that
both breakers are always turned off at the same time, killing power to
both circuits.

Now let's look at this situation:

One of the circuits has a problem and requires it's breaker to trip.
However, that breaker's handle is tied to the adjacent breaker's handle.

What is going to happen when the fault tries to trip the breaker since
the adjacent breaker can't be manually set to the tripped position? In
other words, how is the tripping force on the rigid tie bar going to
deal with the breaker that has no need to trip?