Ok then, hypothetically speaking. A shared connection of a father and son of your example means they are in the same house. All it takes is a question "Hey son/dad, I'm about to launch some attacks to x player, are you by any chance attacked by him or you are attacking him?" they could even leave a note on the fridge if their hours in the house don't match. That is making sure they're not violating any rules. If they are not, then they're subjected to the same penalty as everyone else who breaks a rule. This is equality of all to the rules.
Now, on the hypothetical situation that one of the accounts is the target of an op (fake or real) in which many accounts of a tribe attacks him, it doesn't justify the breaking of the rules for the other account as there are no exceptions in the rule. If a rule is not perfect, it is still a rule that when broken justifies a penalty equal to all that break that rule until the rule is fixed.