A Suspiciously Specific Analogy

Today, I'd like to ask you something.

Imagine that in 1993, Al professes a certain idea for a consumer product. Nothing much comes of it, and the idea lays dormant for a number of years.

In 2009, Al is working at a company alongside Bob. Bob professes a somewhat advanced idea for a similar product. Al, for whatever reason, spends the next year tirelessly, publically and vigorously attacking Bob's idea in every concievable fashion, using every rhetorical, bureaucratic and legal method he can think of to prevent Bob from getting the greenlight for his product idea. He fails to do so, but in the process, Bob's idea begins to bear a resemblance to Al's idea from 1993.

Not that Al lets on, as he remains steadfast in his opposition for the duration, to the point where the sheer intensity of same is eventually turned into a minor Internet meme.

Bob's proposal, towards the end of the process, also reminds people of an idea floated by Chris in the early 1970's.

After Bob's idea is approved, and while pre-orders are being taken, Al begins to tell people that part of the product was really his idea and demands credit for same, while simultaneously calling for the product to be taken off the market.

The question: how long would such a claim of credit last in intellectual-property court?