I've been there.
When I had this happen to me the FMV was slightly higher than my exercise price, but not enough to trigger AMT. I know I only wrote off the actual cash I lost, and I used a CPA to help me make sure I did it correctly.
I guess that's a longwinded way of saying "I doubt it". Tax law around employee options is brutal. :/
c.f. https://www.untracht.com/news-insights/vantagepoint-newslett...
Edit: Consider the case where this were not treated as true. You're clearly not going to pay $2 strike, exercise at $5 ($3 of employment income due to the bargain element), sell at $10 in a later year and pay on $8 of capital gains, right?
For general information on this topic see https://www.irs.gov/newsroom/capital-gains-and-losses-10-hel...
You're certain you were a shareholder and not an option holder? That is, you had exercised some of your options?
Another possibility, since you said it was an acquihire, is the company actually shut down operations and sold off its assets to the buyer. Maybe in that case there would be no share price to report since no shares were bought? I'm not an expert.
I spoke with (paid) two attorneys (employment and business) at the time and they said there wasn't much I could do. In the grand scheme of things it was small potatoes. I was pissed at the time though.