The Planet Express Corporation needs three new turbo encabulators for their spaceships. They solicit bids to produce the turbo encabulators to spec. The

specifications include that it must be capable of putting out three million pounds of thrust in order to launch a ship into orbit. The turbo encabulator also had to

have a enclosure sufficient to survive radioactive conditions. Planet Express expected, but did not mandate, that the bidders would include lead$-$lined enclosures.

The cheapest bid came from MomCorp, so Planet Express manager Hermes awarded them the contract. Payment was made entirely up front, and Mom

began shipping the units from its factory.

Because Planet Express was terribly busy, Hermes ordered his engineer, Rusty, to skip a thorough inspection of the first unit when it arrived. Had it been

thoroughly inspected Rusty would likely have discovered that instead of a lead$-$lined enclosure MomCorp had substituted with an inferior Demron enclosure $-$ a

synthetic material capable of deflecting some radiation but not as effective as lead. Hermes ordered Rusty to install the turbo encabulator abord the spaceship

immediately, arguing that making a delivery would be the best kind of test they could do$,$ anyway.

Two months later, when the Planet Express ship returned the crew had suffered serious injuries due to radiation exposure. Two further turbo encabulators

were still sitting on Planet Express's delivery dock, awaiting inspections. An infuriated Hermes sent a detailed message to MomCorp listing the defects in the first

unit, demanding that they be refunded and that MomCorp pay for the damage to the crew.

MomCorp counters that $1)$ the spec did not require lead, and that Demron can survive some amount of radiation, $2)$ Planet Express has waived their right

to cancel the contract because they already accepted the units, and $3)$ too much time had passed, and MomCorp would not honor any rejection at this point.

Are these defenses likely to be successful?