Pics would help.
If the only damage to your wheel was a flat spot, then your rim was beyond heavy duty enough for the tire you were running. The failure point was the tire. Flat spots happen when when the tire fails to hold up under impact. This happens when the tire is too small, under inflated, or to thin walled for the bike's weight, power, and riding conditions, or if the tire is the wrong width for the rim.
Basically, if you didn't break or pull out spokes, crack the rim, or bend it into a taco, then it's not the rim's fault. It's the tire's.
If we knew what tire and wheel combo you had, we could make better suggestions.