Pirated Adobe products on an external hard drive

An acquaintance lent me an external hard drive that contained a pirated copy of photoshop and I connected it to a computer assigned to me at work . I used this hard drive for weeks and never knew that contained a pirated software. In a vendor software license audits within the company I work for they found it.

They are accusing me of having pirated Adobe products on my computer and tell me that once I connect a device that contained pirated software to my computer I have the burden of responsibility.

Is this possible?

Now I have to pay $10,000 to recover some of the costs which the company will be incurring as a result of the infraction.

The pirated software was never installed on the computer neither copied to it.

I already read the FAQ about piracy but it is not clear to me if I incurred in a crime.

-Chris