[RandomBacon]

By saying it wasn't a company could imply it was another company that someone else asked about that you didn't respond to.

If you say you're not going to answer in a positive, then you also shouldn't answer in the negative.

[jlokier]

Luckily there are a lot of database vendors - it's a crowded marketplace.

So replying once in the negative reveals negligable information and probably does not risk identifying the vendor at all.