I too was puzzled by the post as we are regular flyers with Thai Airways... it's alway been 20kg and 7 kg for carry on luggage, same as other airlines in economy.
We are Royal Orchid Plus members as get 30kg for loyalty.
I'm thinking that whoever weighed in Kitty's bags is giving out incorrect information and possibly let Kitty through without charging excess (just my thoughts)
I read on another forum that Garuda frequent flyer program is reducing their 30kg to 25kg because of fuel costs... only hope Thai don't go the same way as it's one of the main reasons we fly with them... that and their 34" seat pinch and their wonderful flight crew.
Cheers Geri