Concise rules may be broken in case of...
As we noted in the concision rules, there must be some exception. Students often blindly choose the shorter option and find their mistake later. Concision rules are not always true, especially when they are in conflict with consistence rules.
Here are the most common examples that concision rules can be broken:
1) Consistence is needed when there is a parallel structure
2) Consistence to be kept when there is an apposition structure
3) Consistence to be kept with other part of the sentence
4) Consistence with general tone of the passage
When the general tone is in certain verb tense, voice, mood, or other style choice of the author. (Sorry, no example provided here!)