'The collateral damage was not intentional' were his exact words, yes.

[But that was an excellent question, one Ardyn paused to consider. The most obvious answer also seemed the most likely one, so:]

We've no idea how large this facility really is, or if there could be hidden rooms or passages we aren't aware of. A location like that could simply be on another floor or perhaps somewhere we're not even aware exists, much less have the ability to access.