Complete nonsense -- a "Hmong-Thai village legend/hearsay at best."
Yog khub niam txiv/hluas nkauj hluas nraug nod mus "sib ua" tom tus tswv teb tsis raws cai nod mas hais tsis tau nawb -- yuav tau kho tus tswv (penalized, and could involve "ua neeb", just depends etc.). Hos kom nkawd cia lid "ua neeb/hu plig" nod mas xyov yog tseeb los cuam/cuav, ntshe lus taug xaiv xwb los lam tsis tau. 9/10 times ces yog nplua xwb -- a monetary restitution.
In traditional Hmong culture/etiquette (kev cai), it has to do with more "respect" versus "superstition", though some incidents are believed to invoke bad omen.
Examp: If you (lewd birds), out of disrespect for your parents, while they are away, or are not home, decide to bring your "lewd bird" over and FLUKE in their house, then expect bad omen(s)/turmoil down the road -- effecting the entire family, especially your parents' marriage. Yeah, this is arguably "superstitious", and would/may require "ua neeb" to correct, which I do not care to go into. (So definitely not so much "superstition", but "respect/responsibility", more than not.)