You'll have to forgive me here but I had no idea who Chris Kyle was until the controversy over American Sniper made its way over the pond to the UK.
I've read a lot of reports about this film and Chris Kyle's autobiography and there are numerous discrepancies cited by the bloggers, researchers and reporters. If Jesse Ventura successfully sued Chris Kyle's estate for Defamation of Character, which I believe has a huge burden of proof in the US, far more than in the UK, then surely he has been proven right by law and Chris Kyle has been proven to have lied in his biography?
This is an honest question from a foreigner, so please take this in the spirit it is intended, which is not one of antagonism or trolling in any way.
Not really, no...defamation essentially says that he, quite simply, defamed Jesse Ventura by stating that he punched him in a bar for anti-American sentiments. Jesse Ventura is a well known nut case...he was an actor, turned extremist political figure, and then became a governor (which I still remember people being completely baffled by and laughed about because it was, almost assuredly due to his financial ability and popularity from his celebrity life...much like Ahhhhhnold in California).
The actions listed in the book could have been 110% factually accurate and provable, and Ventura could still sue for defamation...it's kind of a sleazy type of suit most times because it means that the person did something defaming, another person referenced it, and they don't like the fact that it was made public. There are cases where it's done under situations where the event was totally false, but those are usually followed with other types of suits, not just this one.
At the end of the day, Chris Kyle became very popular due to his service in the military and his autobiography...he made a lot of money from it, and because movie rights were purchased with big names attached (Clint Eastwood, Bradley Cooper, Sienna Miller), Ventura's legal team saw an opportunity for easy money, and went after his estate.
It's despicable in my opinion.
As far as the discrepancies you mentioned you read about...I'm sure there are things that people have different accounts of, every story has multiple view points. From what I've read though, the people who spent the most time with Kyle, even people who were not overly fond of him, said that his accounts were extremely accurate and represented very fairly. We may not ever know what is 100% truth, but honestly, what does he have to misrepresent? What purpose would it have served?
Also, what purpose would it have served the film makers to misrepresent the book? I mean the source material was Chris Kyle's own book...movies will be dramatized and sensationalized for entertainment value, but so far, I haven't read anything that stood out to me as a legitimate misrepresentation or discrepancy...mainly just agenda pushers trying to poke holes in a very successful bio-pic.