RE: DLE-111 first start... warranty used, but things are looking good.
Happens all the time with 4 stroke glow engines too. The situation is not limited to gas and extends to all engines.
Improperly installed, any prop can fail. The manner is generally dependant on the mode of installation. Carbon props generally require more force to generate explosive failure than wood. Wood is more sensitive to shock damage than carbon, but both go to pieces quickly upon contact with things in their rotation plane. A certain level of knowledge is required of anyone intending to use a propeller of any type. Failing to possess that knowledge can be dangerous for the user and anyone around them, regardless of the propeller composition.
This is why we've been telling people for many, many years not to stand in front of propellers when running up engines. It's why we don't have our planes pointing at nearby spectators when we start engines. It's one reason why you should never tune an engine from in front of it. So don't panic. The danger isn't any greater than what you've been subjecting yourself to for as long as you've been flying already.