The tapes are the only evidence against him. It's not like he was the one that actually carried out the crimes. If those tapes are inadmissible, the case relies on an informant who is currently being investigated along with 3 FBI agents for improper procedures during the case. Credibility is everything to a jury and these guys have none. Merlino made a couple million from the healthcare fraud scheme, so a $100K in lawyer fees is worth it.