I DO think it is operator error in this. While I'm sure people can say they DID NOT lift the saw head after the conclusion of the cut, and that they DID wait for the blade to fully stop I personally don't believe that is accurate. I have owned 6 Kapex's, 2 Currently, numerous DeWalts and Makita's and I have had kick back that broke parts and I can honestly say they are from ME raising the saw head with the blade still spinning and small cut off's on the saw base. It's not about blaming one person or the other, but really... try and understand what you are saying. The saw just spins a damn blade. Where's the design flaw that some of you mention. There are several blade manufacturers for the saw so you can try other blades, it has a fence, a base, they are for the most part at 90 degree's to each other. The blade spins and can be mitered and beveled. Where the hell is the flaw in that???
It's only my opinion... But I believe all you master saw users that have never had a single issue before now, do so because of the Electric brake on the Kapex, which is also a fairly new feature on other brands. If you think about when a small piece gets kicked back on a table saw, etc. it's when the blade has slowed and not generally at full speed (think about that piece trapped between the table saw rip fence and blade that you for some reason can't clear. I think it's that the blade is slowing and is prone to pick those pieces up and throw them, and yes it is because you lifted the saw head. You may not have intended to, and you may not think you did... but you did. I don't see this as a flaw, but may be different than what you are used to operating. There are benefits to having the electric brake and your methods should change accordingly.
I guess we could do some experiments lifting the head a full speed, etc. and see when the issue occurs, but I have years of experience and many thousands of cuts with the Kapex and DeWalt and other saws. I have had the issue with the Kapex and know it was I that lifted the saw head before it stopped. Show me a video of it kicking that piece up with the saw head down and/or it happening to me and maybe I'll change my mind, but fact is it won't. Sure it's nice to have someone pay for our mistakes, but c'mon. I know it's an expensive saw and I would buy them all over again because I absolutely love working with the Kapex vs the miter saws I worked with in the past.
There are issues cutting small moldings where the piece will practically explode when mitering and it's not that it's just the Kapex that does it as you'll read in some of the links below. I have personally had great fortune cutting these small moldings by beveling, rather than mitering. I don't know technically why but in real practical terms it makes a huge difference. I can probably make a video of that phenomena if anyone cares.
Again... It shouldn't be about blaming a tool that just spins a blade, but rather what can be done to minimize and or help prevent the recurrence of the kick back issues.
Just to see that there are more than Kapex users that have issues with kickback, you don't have to search hard.
https://forum.canadianwoodworking.com/showthread.php?21204-Mitre-saw-kick-back-sore-finger!!
http://www.woodweb.com/knowledge_base/MiterSaw_Kickback_Injury_Story.html
http://www.diychatroom.com/f14/miter-saw-kickback-oak-quarter-round-129117/
http://www.woodtalkonline.com/topic/12477-miter-saw-kickback/
http://www.sawmillcreek.org/showthread.php?9930-Miter-saw-kick-back-problem
http://lumberjocks.com/topics/13849