I think the biggest issue is they were not patient enough to work through the Bureaucracy to do it Legally.
I bet if they had bugged enough people for long enough in the FAA and had agreed to stipulations by the FAA they could have received the exemptions and/or waivers needed to do so.
Also mentioned they could have probably moved the stunt outside of the USA, but that would have cost more money and time.
example of it working...
http://www.soarkansas.org/soar/Stories.aspx?s=31
"I was told by a FAA man many years ago that you can do anything if you go about it right."
Brian