DY:
You wrote:
“but if the school doesn’t have the money, they don’t violate the איסור of לא תלין or the עשה of ביומו תתן שכרו.”
Can you please provide a citation that this is true. I might understand a dispensation of אונס, but you imply that there is no issur. Please reference.
Neville:
You wrote:
“For one, they’re protected by mesirah and they know it.”
Not only that, but it is extremely rare to find a beis din that will ever accept a case involving a yeshiva/school. They cannot face a consequence in a secular court (actually the issue might be better termed arka’os – mesira implies a criminal report), nor are they at much risk of a psak beis din against them.