What they say there is:
"The basic information you need to know to differentiate these two malts is this: Caramel malt is applied to both kiln and roaster produced caramel malts, but the term crystal malt is normally reserved for caramel malts produced in a roaster. Logically, the term crystal malt should be reserved to describe malts that are truly crystal in that they exhibit even and consistent crystal like, glassy kernels which is possible only by roasting. If we accept this terminology as being appropriate, then it should be realized that all crystal malts are caramel (type) malts, but not all caramel malts are crystal malts."
So, kilned-produced malts are always caramel malts but roaster-produced malts are either Crystal malts or caramel malts, depending on the extent of even and consistent glassiness (which only comes from roasting). Now the hard part - pick out the difference in taste!