Help Please on the realty dispute !! 單身老貓 , Expert!

We sold our old house on Aug 5, 2019. We bought that house in 2011. We then added 
an addition (the original builder of the house) and the pool in between 2015-2016.

We lived in that house more than eight years. We love this house.  The reason we sold this house was my husband changed job to different city. This house is perfect. The only one small events happened was several months after we moved in 2011. One day We found water came up of the bath tube. We then called plumbing service, they came and did the service, the issue was resolved. Ever since then the house had no issue. The house was in excellent condition when we sold it. Passed the buyer's inspection.

What should I do? How to deal with such bully? The money they demanding is scary!

Please help.

Thanks.

Queen

   ==================Letter received today from buyer's lawyer==============

所有跟帖： 

• 没disclose ？这些他有据可查的比较难否认。 -julie116- ♀ (0 bytes) () 10/03/2019 postreply 20:31:02

• Again 單身老貓 , Expert! please shine some light!! Appreciate!!! -yingjianyu- ♂ (1597 bytes) () 10/04/2019 postreply 16:58:36

• 法律上我不懂的是：是他们有责任证明你们知道，还是你们有责任证明你们不知道？ -N.- ♀ (911 bytes) () 10/03/2019 postreply 22:34:35

• the pipe were never touched. We had no plumming issue. -yingjianyu- ♂ (307 bytes) () 10/04/2019 postreply 10:47:57

• 对方要证明你知道，或者你应该知道。 -柠檬椰子汁- ♂ (692 bytes) () 10/04/2019 postreply 06:54:47

• +1 -7000miles- ♂ (0 bytes) () 10/04/2019 postreply 07:18:34

• 千万不要赔钱，赔钱说明你认错，后续估计会有其他赔偿要求 -from中国- ♂ (0 bytes) () 10/04/2019 postreply 11:13:51

• 是买家自己请的inspector做的检查吗，你的出售合同上标注是“AS IS”？ 还是找律师吧 -湖房- ♀ (0 bytes) () 10/16/2019 postreply 13:15:19