"You made this? I made this."
Of course a conspicuous architecture would still give it away.
Step 2: European company distills or just adjusts the model slightly, and publishes its model on HF
Step 3: American company uses model from step 2. Has to testify under oath where they got it from. "We got it from these French guys"
Or you think all kind of fraud can be committed through some "french guy"?