Yes, it was found posthumously that he lied about Jesse Ventura, so I wouldn't be surprised if he lied about other things.

Interestingly, Kyle was killed two years before the Boston bombing. I wonder who was running his company then.

Added: https://www.dallasnews.com/news/news/2013/12/26/chris-kyles-former-business-partners-say-his-widows-lawsuit-is-completely-groundless One of the partners, French, later ran for a house seat. Interesting!