A bowing basement wall can exist without a basement leak being present. The walls can be pushed in by expansive soil. This soil, when excess moisture is present, creates the pressure that moves basement walls. Just because the basement is dry, does not mean that there is not excessive moisture in the soil.
A bowing basement wall can also be caused by roots, freeze pressure, excessive vibration, and many other factors. It is important to understand the cause of your bowing basement wall. This allows a repair method to be designed for the specific cause.
Some walls can bow due to a previous basement leak repair! The photo below is the results of bow due to incorrect backfilling procedures by another contractor.