What could explain "Search" was that the destruct sequence was rigged to use ordnance to blow the bridge area, decisively erasing all data and technology. Then, they breach the core to destroy everything else.
That's a bit of an overkill, all you have to do is destroy the processing unit of the computer which should be n'tvery big. You don't even need an explosion just a massive overload that will melt it. Computers are usually more fragile than starships.