Would the one "not touched", ignoring the error (even he would have the possibility, skill and means) be regarded as higher?
Or the one taking on a correction (even if not having best possibilities, skills and handicapped ways, nevertheless by skillful means)?
My two cents:
It is not easy to come to a conclusion from the behaviour alone.
A1. Ignoring the error due to indifference/apathy, not caring for whatever the outcome or result.
A2. Not interfering with it, because there is good in everything and allowing the natural process to evolve - not siding with push or pull to change the outcome one way or the other, but staying with it, observing one's reactions as well as accepting things as they are.
B1. Correction being done because one cannot accept the presence of an error, a reaction to correct things based on one's view of how things should be.
B2. Correcting because of compassion, in-order to benefit all the beings that may chance upon this.
To me, both A2 and B2 are equally good, as they are a display of true equanimity and compassion, respectively. A1 and B1 are not actions without demerit, but B1 is slightly better in a sense because there is a greater chance to learn from it than A1 (going ahead and committing even a mistake is better than totally ignoring it, in my opinion).
Of course, in a community managed site like this B1/B2 are the better options, but in regards to right action for mindfulness practice/self development both A2 and B2 should rank equally.