Hi there - let me speak on behalf of the Kyle David Miller Foundation on this topic.....seeing as I am on the Board of Directors.
There are many points covered by the foundation today - encouraging children to remain in a 5 point harness car seat for a myriad of reasons and encouraging children to remain rear-facing to the limits of their convertible seats are the two which pertain to child restraints.
Yes - Kyle's seatbelt failed in a rollover accident. He was in a booster seat and thus was ejected from the vehicle. When ejection occurs, the results are almost always fatal for the ejectee. At the time, Kyle had outgrown his 5-point convertible seat and his family were unaware about higher weight harnessing seats that were available (mainly only online rather than in stores). They thus made it their mission at the time to ensure that parents were more aware of these higher capacity weight seats so that other parents would potentially avoid their heartache. That grew into the foundation that exists today which spreads both awareness of the benefits of keeping a child in a 5-point harness for as long as possible and donates these high weight harnessing seats to families in need. In 2007, the foundation donated over 300 seats, and raised awareness about extended harnessing which resulted in these seats being available at your local baby stores rather than just online.
In specific answer to your question about LATCH vs. seatbelt and would he have been saved even if the seatbelt had failed......there is no data today to suggest that LATCH is safer than seatbelt - both are mechanisms that can fail. A correctly installed and used 5-point harness seat which is also top tethered has:
a) potentially less chance of ejection from the vehicle
b) spreads crash forces over 5 points of the child's body, holding the child in position rather than the potential of being out of position in the booster/seatbelt combination.
c) prevents the submarining effect that can happen in booster/seatbelt combination.
There is a very nice write up about why a 5 point harness is safer on the foundation website. (
http://www.kyledavidmiller.org/pages/4211/Car_Seat_Safety:_5-point_Harness_is_Safest.htm) I recommend that you take the time to look over the foundation's website and am sure that all your questions regarding the foundation and our message will be cleared up.
If you have any outstanding questions regarding the foundation, our mission and message, please contact us through the website and I will be happy to personally address them.