...at the company where I work they stress to each employee not to work with certain companies (and Iran is on the list) because if we do we will be in violation of US Export laws and the US government could decide that we can't export anything to any other country. That would cause me and just about every other person in my comany to lose their jobs.

That's not proof that a big company like HP wouldn't do it; just that they'd be creative in finding ways around the export restrictions.

And if they really weren't aware that this has been happening, this would be a good time unload stock in a company that hasn't got a clue about due diligence. Compare this to e-waste disposal. My company audits our e-waste recyclers, who audit their downstream recyclers, to make sure our used computers don't end up in an illegal e-waste shipment to China. If HP doesn't periodically audit its distributors, especially those in the Middle East, they're doing a pretty crappy job of covering their asses against federal prosecution--especially if the distributor boldly stated on their website that they distribute to Iran.

Has HP unknowingly been supplying Iran with technology

Only if you put big finger-quotes around "unknowingly".

On the other hand, maybe this is a secret government plot to bankrupt Iran by selling them cheap printers, then gouging them on cartridges.