Citation 2 has explained brilliantly.
That kind of situation where there is several safe possible decisions is a situation where you want to find the optimum decision. To achieve it, it is good to resort to one of those mnemotechnics, like DODAR of FORDEC, get all the facts, consider several options, evaluate them in terms of safety, legality and efficiency, get input from your company and your FO, and make a decision. The outcome should be the best possible given the particular circumstances. This circumstances could be radically different the next day, mind you.
A quick "let's return" or a "let's go on, the airplane flies nicely" decision is not advisable. You have all the time in the world to think about it.