My guess is that some moron was using the restroom and decided to smoke a cigarette and noticed the smell of the sulfur was considerably stronger and he no longer could smell his fecal matter!!
Don't Forget To Burn A Match..... What Is It About Striking And Burning A Match That Eliminate Odors, Such As In The Bathroom?
The smell comes from sulfur, and I agree with Jillcherie, it was probably someone lighting a cigarette or candle, and noticed the match covered the smell
