This is the kind of problem that happens. Through such unestablished or weakly established extension of rules and through false analogys, a complete new set of rules emerges and the punishment adultery becomes altogether something else.
In today's time anyone trying to Islamise the state should start by establishing those aspects of Islam upon which the four schools of thought agree. And new issues should be similarily based on widespread agreement of Muslims all over the world. Aspects which are obtained through Ijthihad (past or present) over which agreement does not exist nor immediately evident should be left out when it causes unnecessary burden among Muslims.
Whats is also worse is when punishment is used as an attempt to show off their Islamic character. An outward hypocritical show which even a layman can recognize and would despise. Or when pubishment is done to make a statement to the "kuffar west" or conduct witch hunt against rivals.