However, you might also interpret it to mean that if there’s a single woman wearing shorts or a priest who once had a lay witness speak after the homily, you’re completely in the clear to attend whatever irregular mass you want based on your own infallible interpretation of canon law.
A member of the congregation wearing a short skirt is one thing, but liturgical abuse is another matter.
It could be argued that in such circumstances it is not a doctorate in Canon Law that is required, but an honest judgement of conscience?
If, hypothetically, a Catholic has experienced regular liturgical abuses at a Mass celebrated by a priest in ‘good standing’, is deeply concerned about such abuses, has charitably approached the priest about these, perhaps even approached the bishop, possibly even written to the CDW, but the situation continues, then would that not represent (after an honest, heartfelt examination of conscience) a moral impediment from attending such Masses?
And if there were no other Masses from priests in ‘good standing’ available within reasonable travelling (and the travelling issue would be another judgement of conscience) or if a similar situation regarding liturgical abuses was occurring in other nearby Masses (again that would require another judgement of conscience) would that not be another factor?
However, liturgical abuse should be judged, not against how the individual thinks it ought to be, but against the current norms of the Church and the norms determined by the diocesan bishop, with reference to GIRM, Redemptionis Sacramentum, Canon Law etc. The judgement would have to conform with current Church law.
Given the standards at which liturgical abuse must be judged, it would possibly not be unusual to have a church where liturgical abuse is quite regular, but it would also seem improbable that there would not be priest in a church at reasonable travelling distance who will be saying Mass word and action perfect as per the GIRM.
So for the majority of people, it would seem that the chances not being able to attend (within reasonable travelling distance) a Mass said by a priest in ‘good standing’ and said as the Church says it should be, would seem to be quite slim, but not impossible.