Due diligence
I once went and did some due diligence on some computer systems for a company that was buying another company which 'used the same core software'. Their plan was to merge platforms to create cost savings.
After a week I came back and said... "it is physically impossible to run their database on our platform and software version. It's not possible to merge the two. Theirs will always be separate. They also have contracts which require segregation within their own systems."
Management chose to disregard my report and bought the company, insisting they could merge the platforms. Five or six years (and some large losses) later they resold that company for a fraction of the price. The platforms were still resolutely separate.
With zero knowledge of the reality, I don't doubt someone told HP that that Autonomy didn't quite measure up, and HP will have chosen to ignore that.