The lecturer talks about research conducted by a firm that used the group system to handle their work. He says that the theory stated in the passage was very different and somewhat inaccurate when compared to what happened in reality.
First, some members got free rides. That is, some didn’t work hard but got recognition for the success nontheless. This also indicates that people who worked hard were not given recognition they should have gotten. In other words, they weren’t given the opportunity to “shine”. This directly contradicts what the passage indicates.
Second, groups were slow in progress. The passage says that groups are more responsive than individuals because of the number of people involved and their aggregated resources. However, the speaker talks about how the firm found out that groups were slower than individuals in decision making. Groups needed more time for meetings, which are necessary procedures in decision making. This was another place where experience contradicted theory.
Third, influential people might emerge and lead the group towards glory or failure. If the influent people are going in the right direction there would be no problem. But in cases where they go in the wrong direction, there is nobody that has enough influence to counter the decision made. In other words, the group might turn into a dictatorship, with the influential party as the leader, and might become less flexible in its thinking. They might become one-sided, and thus fail to succeed.