It is quite normal for a bike manufacturer to use the same frame, outfitted with different equipment, to cover two spots n their bike line-up. Generally, for a road frame to be used as a TT or Tri frame, a forward offset seatpost and an aero bar are the main changes.
My first thought when I saw the pic of your bike was that it was a dogs breakfast of parts, the mismatched frame and fork brands being the most obvious. This is not to say that the parts are wrong or somehow incompatible, just that it doesn't look like a 'factory' bike, but one that was put together by a previous owner, or by a shop looking to put a handful of otherwise orphaned parts to use.
As for your assessment of Kastle as a 'reputable' bike manufacturer, I personally didn't know they made any bikes before I read the OP. I wonder if Kastle is not so much a bike manufacturer as they are an alpine equipment manufacturer who sold the rights to use their name to another entity who makes bikes, and the people who make Kastle skis etc, may or may not have anything to do with the bikes. Also, I could not find any evidence that there are still bikes being made under the Kastle name.