The plaintiff (=pl) hired a building company (=def) to build a home. After several months of work, pl stopped the work, as allowed for in the contract, due to several complaints of delays and faulty work and after having paid 110,000 shekels. According to estimates of an external engineer, the work completed was worth 20,000 shekel and so he demands that 90,000 shekel be returned to him. Def disagreed with many of the details involved in determining how much money he deserved for his work. Ruling:
[In many cases, there is doubt as to how much one has to pay another, and the concept of muchzak, that one who is possession of the object or money in question has the upper hand regarding that which is in doubt, plays a major role. One of the major elements of this case is to determine who is muchzak.]
Pl claims that since he gave much of the money before it needed to be given, he should be considered muchzak in regard to that money. However, since pl gave the money willingly, it is not a case of unlawful seizure of funds, and thus def is legally in control of the money he received until proven otherwise. He would even be able to be believed about another claim regarding which he could say that he is holding the money (Shulchan Aruch, Choshen Mishpat 75:7).
Pl claims that the agreement was based on a misrepresentation (mekach ta’ut) of def’s ability to do the work that was needed, and therefore def should receive compensation for the work he did only like one who did work without permission. However, mekach ta’ut does not apply when pl could have checked def’s qualifications and did not (see Ketubot 76a). We must assume that pl was satisfied with def’s qualifications to the extent that he was interested in checking (unlike an object one buys which looks normal but could end up being flawed in a hidden way). Furthermore, since pl was able to see the professionalism of def’s workers and afterward was willing to continue paying, then even if there were originally grounds for mekach ta’ut, he would have relinquished those rights like one who continued using the flawed object after uncovering the flaw (Shulchan Aruch, CM 232:3).
As a worker who worked with permission, def deserves to be paid the higher amount between the value that he added and the amount he spent on the project (Shulchan Aruch, CM 375:4). In this case [for reasons too complex for this treatment], the only feasible measure of appropriate payment is based on expenditures (including for workers) that def incurred. He should generally be believed about this if he swears and/or provides proofs. In a case where this cannot be done exactly, beit din has the obligation to use its discretion in piecing together def’s claims in this regard and pl’s objections and to come to a realistic appraisal (based on Shut Harosh 107:6). We cannot rely upon the engineer’s appraisal because he based it in on the accounts of the work done as depicted by pl, who also hired him.
[We will not go into the rest of the lengthy ruling.]