If it is a situation where you are certain you could positively impact it without negatively impacting yourself and others, then I wouldn't say it's immoral to not do anything, but I would say it's moral to do something. The two don't necessarily need to be present in every situation together.

However, trying to impact a situation without certainty of the results is reckless to the point it could be considered immoral, as your carelessness could cause more negativity than had you not interviewed.

In short, it is not immoral to not act, but it could very well be immoral to act.