I hope you didn't recieve any injuries when that happened!
That looks like there was material defect in the steer tube. Looks like the metal had an existing crack that went unnoticed in manufacturing. Of course proving that to Cannondale would be next to impossible unless it happened when the bike was brand new, not 13 years later. They would claim it was poor maintence on your part now. SHAME on them but that is reality.
Answering your question about frames made in Taiwan, my 2020 Habit aluminum frame looks and feels every bit as sturdy as my USA made bikes. The finishing on the welds are not as nice as the USA made bikes, but that is strictly a cosmetic thing not structural. The bike has survived several four to five foot high drops while jumping off features on trails. My aging body doesn't like it as much as the bike handles it, that's for sure.