Believing he lied doesn't equate to bias nor do those who believe he lied necessarily believe he 'colluded' in the sense that is being pushed.
We do know he lied. Right now, the defense is 'he just had business dealings, like any developer' but not long ago, he completely denied any business dealings whatsoever. This was something he didn't need to lie about, but he did anyway. Having business dealings was not wrong or improper, but he still felt the need to lie about it.
Even the biggest (OK, maybe not Gateway Pundit big.. but up to that point) supporters admit he did lie about this.