You could say they just reverse-engineered Brio's product, and therefore it wasn't theft.
But the presence of the Brio sample wine DB appearing on MS Office boxes showed that they bought a copy of DataPivot and used that DB when developing their clone. They didn't even bother hiding the evidence.
BTW, DataPivot was released in 1991, and the only other references I've seen for prior art are a Lotus product released about the same time.
It's not clear that you understand the question you are answering. The "product" being referred to here is a centuries-old concept. There is nothing about pivot tables themselves that Microsoft would need to reverse engineer.
The comment you are responding to is not challenging your use of the word "stole" — it is asking you what exactly MS is alleged to have stolen, reverse engineered, or otherwise gleaned from your former employer.
But the presence of the Brio sample wine DB appearing on MS Office boxes showed that they bought a copy of DataPivot and used that DB when developing their clone. They didn't even bother hiding the evidence.
BTW, DataPivot was released in 1991, and the only other references I've seen for prior art are a Lotus product released about the same time.