[Ray76]

2 years of data loss means the loss was recent (you can’t lose future data)

A hardware failure would have generated a trail documenting the failure and replacement of the hardware, and likely data restore to the failed disk. Hardware support persons or contractors will have artifacts documenting the failure, a few examples: support tickets, hardware monitoring logs, or emails.

Make them prove there was a recent failure. Make them explain why certain data could not be restored. etc.

[Maurice Tift]

  contractors will have artifacts documenting the failure, a few examples: support tickets, hardware monitoring logs, or emails.

  Yes - certainly they know which contractors they paid. There must be some sort of dated documentation - unless the entire incident is a fabrication. The lack of any documentation would indicate that the entire hard drive crash story was a lie.