Let's just stipulate that if we're on this guy's jury, he's innocent until proven guilty under the law.  I think that's a given.

But we aren't on the jury, and that allows us a looser standard when forming an opinion.  I didn't see George applying an "innocent until proven guilty" standard to Tim Geithner upthread when he called him a "crook" and a "federal tax cheat", nor did I see any admonishment from you that he wasn't keeping his mind open because he didn't apply such a standard. 

When George called Geithner a crook, I certainly didn't make an argument that Geithner wasn't a crook simply by virtue of the fact that he has not been convicted of a crime.  Beause let's face it, there's a lot of crooks walking the streets free because of technicalities, bad jury decisions, clever legal defenses, and the pure luck of never getting caught.  Instead, I argued that I didn't believe Geithner was a crook based on the facts of his tax issue.

Similarly, in this case, I'm saying that if the news reports and the extra info provided by Dave's source accurately represent this guy's scheme, he's a crook.  He may never be convicted, or even charged in the case-- he's still a crook.  A criminal is a criminal, whether they get convicted or not, and an innocent person is not a criminal even if they get convicted of a crime. 

Bottom line: if I see a thug beat down an old lady in the street and run off with her purse, I don't feel any particular obligation to wait for the conviction to call the guy a criminal.  Same general principle applies here.

As far as the tax avoidance schemes you describe, I think I'm fairly safe ground when I say that many of them in fact are not legal-- for instance, sham business transactions that have no legitimate purpose other than to avoid federal tax are not legal.