US law requires that the allowance for the marketing carrier of the first segment applies to all segments of the same ticket. The allowance for the first segment is one bag at 50 lbs. Additional weight and pieces is a waiver and has no effect on downstream carriers.
Thus, at a minimum, you can expect KA to collect the overage. At worst, KA won't honor or understand the DOT rule. KA doesn't operate in the US, so there really isn't much that DOT can or will do.