Here's how I see it...
... Blair claimed there were WMDs that could be deployed against Britain within 45 minutes, so he's either a liar or incompetent (or both).
If I were about to commit our armed forces to invade a foreign country I would want to know what weapons that country has and the capabilities of those weapons. Blair has since said he was not told the 45 minutes claim was only for battlefield munitions. If he didn't bother to ask the basic questions about what sort of weapons could be deployed against Britain and its troops then he is guilty of sheer incompetence.
On the other hand, if he did know all of this and yet still repeated the 45 minute claim then he is a liar. Since we know no-one has been fired for not telling him the 45 minute claim was only for battlefield weapons I think we can safely assume he's a liar.
So take your pick, either way he's still guilty of participating in an illegal war.