Structurally that is almost guaranteed to be a bad deal. I doubt you'd ever find a deal of this form in the history of a startup that went on to be successful. If an investor buys as much as half the company (it does happen in some series A rounds), the valuation should be higher.
Investors might pay $200k for half a restaurant or some other business like that, but not a startup.
Yes I think the professor realised this -- he was one of the founders of lavalife IIRC.
I have seen the show and my observation was: The dragons are really mostly into funding sauce-makers, innovative clothing accessories, etc. and they apply the same principles to startups -- doesn't work well.
Investors might pay $200k for half a restaurant or some other business like that, but not a startup.