What would you do?

I have a situation here, during a design exercise. Imagine:
You got a great ID concept (spent lots of time looking for it) & illustrate via AI.
Your friend saw it and make another similar one using Freehand MX.
Your boss (he only use MX) open your friend design and love the design.
Later (2-3 hours) your boss came to see your design and said,
Owh… this is similar to the other concept -put away this concept and make another.

How shuld you feel?
& What would you do?

Talk to your friend and your boss and get the story straight.

I disagree. I say “turn the other cheek.” Prove your worth as a designer by creating another dozen great concepts.

But if it happens again, make him tell your boss where the concept really came from. Only escalate it to your boss if he refuses.

And if you need evidence for who’s came first, just show your boss the “created” date on the file info.

Im really pist of this improper work ethic, and Im disgust to even talk to the other designer. Im going to ignore this for now.
Its tough to produce another concept when youve already put all your effort/mind/hope to the first concept.
Fyi, the fake concept is going for 3d process now. Tanks for your reply guys.

Another thing is, this wont happened if we had a proper discussion on concepts we had with the boss, it suck when the boss (design principal) dig into ppl work and select concept without understanding the concept from its own designers, and the concept is not even finish yet. Sad.