The real mistake is not correcting a mistake when you see you've made one.

It's always hard to let someone go, especially in a small company with a focus on personal development and a positive work environment. However, if you don't address this situation:

  1) The morale of the company will likely decrease.
  2) The productivity of the team will suffer.
  3) Employees may start questioning the leadership's decisions.
  4) Some may consider leaving as a result.

Generally speaking, the well-being and efficiency of the entire team should be a top priority for the company. From this, it also follows that having a solid interview process is crucial.