I think that bit is just for show to indicate they are interested. Afterwards they probably look into the details and the investment is then confirmed, contracts drawn up etc.
What I found interesting was how most of the pitchers were so hesitant to give away much of their company in exchange for the money. If you go to a VC they want a large chunk of your business - offering them 10% is hardly worth their effort in paperwork. The other thing is that some of the amounts were not that big and could easily be obtained from Business Angels or other sources, as one of the investors said.
Gary