A nano-summary:
There was a certain homogeonaeity of views on the panel, for the reasons given in my post. When a member of the audience tried to raise this, they were roundly slapped down.
The panelists described the difficulty of getting accurate data on trafficking in sex work but all of them, including John Birch of the police’s vice unit, felt that it was a small minority. They all believed that criminalising the majority was not the most effective way to help that minority. They also believed that criminalising clients (which the UK is currently considering) would make matters worse. John Birch described walking a tightrope between a duty to uphold the law (which criminalises sex workers unless they are working in complete, and often dangerous, isolation) and a duty to protect citizens (because let’s not forget, people who take cash for sex are as much citizens as people who have sex after being taken out to a nice dinner or to the altar).

Yet again, we heard that the sex industry does indeed include trafficking, exploitation and violence. Just like the construction industry, and the meat-packing industry. Yet again, we heard that the solution to these issues is to tackle them in their own right, rather than to ban the sale of sex, or the building of offices, or the eating of meat. Yet again, the discussion will probably have no impact at all on a government driven by moral conviction rather than common sense.