An analogist might propose that 'any greater sin during prayer must also invalidate ablution'. First, however, it must be proven that the specific ruling on laughter rests on the degree of sinfulness. The legal consequence alone does not establish that cause.
Comparison:
Audible laughter: a special ritual consequence discussed under particular evidence and conditions.
False accusation: independently grave and prohibited, but severity does not itself establish a new ablution rule.
This makes the first condition operational: an established textual consequence cannot be changed or extended merely by apparent resemblance. Nor should the example be presented as an undisputed rule across all schools.