So they keep millions of dollars worth of samples in a single freezer in a single location?

The loss of the samples was an inevitability and regardless of who pulled the plug - a cleaner, a power cut or a faulty compressor they are solely responsible for the loss.

Assuming a cleaner would read a note attached to a freezer, given they no doubt have to see lab notes all over the place - and probably have instructions not to move or read the notes - is completely delusional.

IMO the blame falls squarely at the feet of the researchers and RPI and at worst the cleaning company should agree to terminate the contract (thus losing the $1.4 million per year deal they had).