Bava Metzia 112: Punishments, Conditions, Oaths Regarding Withholding Wages

The rabbis continue their discussion about workers' wages.  We are introduced to a baraita that teaches that because a worker risks his life by going up high ramps and trees for wages, one who withholds those wages is like one who has taken away the worker's life.  The rabbis argue that perhaps the baraita refers to the employer's life, too.  In fact, the employer might be meant to be worthy of death for leaving a worker in such conditions with no reward.  

Does a worker have to ask for his wages for the employer to transgress by not paying those wages?  Are there certain conditions where this might be true, like if an owner pays a grocer or a moneychanger?  The rabbis do not find a proof text for this based on wording.  However, if the employer and worker made such an arrangement in advance, might this preclude the transgression?  And what if this was the agreement, but the grocer or moneylender refuse to pay the worker?  Can the worker claim his wages from the employer?  The rabbis disagree about the employer's liability in this case.

The Gemara then considers whether these same rules should apply to a person who has been hired to complete a task for a fixed price.  In these situations it seems that the craftsperson might not return for his wages immediately.  Does the employer transgress if he withholds those wages?  If improvements are made to a vessel, for example, is the vessel simply on loan, for the employer will eventually pay the cost of the improvement to the vessel?  Using the example of a garment brought to be repaired, the rabbis wonder if the person is permitted to waits to collect his garment and pay for the repairs.  And by what time are those wages due?  The rabbis wonder about what constitutes improvement to an item through some interesting examples.

Our last Mishna had taught that when there is a conflict regarding wages, the worker swears an oath and then collects his wages.  Why is this the opposite of most other conflicts regarding denying a debt, where the employer would swear an oath and collect.  Perhaps, they argue, this was decided in order to ensure that workers would be available to work for employers.  But employers would find others to work and workers would find different employers, so, they decide, this is not the case.  Perhaps the employer forgot to pay, but he feels better to know that workers are willing to swear about their payment.  Perhaps workers should be paid before their work with witnesses present. But no-one wants this; employers are afraid that their workers will leave and workers are afraid that they will lose their wages.   Finally, the rabbis note that everyone should remember their agreed upon wages.  When the Mishna says that employers do not swear after payment is due.  Even if he did forget to pay the owed wages, wouldn't he find the motivation to remember in this sort of situation?