The nature of a false Heter is often such that it does not fulfill its own terms (such as those who wear sheitels (wigs) including in areas these are unknown, contra Mishna Berurah 75:15). Here’s another example: smoking on Tisha Be’av. Many are those who repeat the slogans about always following the Mishna Berurah, no matter the other opinions or the strength of the MB’s specific position. Yet some of these individuals are shown in a bad light when it comes to Mishna Berurah 555:8. The MB clearly limits his dispensation to smoking in private, yet they do so in public as well.
This is especially jarring because the rhetoric regarding their opponents is of excommunication (as always!), but that is what the MB nearly recommends for them!
Here is the aforementioned MB:
אסור לעשן טיטון (שקורין רייכערין) אפילו בד’ צומות וכ”ש בט”ב [כנה”ג] והחמיר מאד עד שכתב שמי שמעשן בט”ב היה ראוי לנדותו ויש מאחרונים שמקילין וע”כ מי שדחוק לו שמורגל בו ביותר יש להקל אחר חצות בצנעא בתוך ביתו וכ”כ בשע”ת בסימן תקנ”ט סק”ג