Yeah, I don't recall it either - I've actually got that book. Lusankya literally tearing Coruscant a new one? Hell yeah. But that bring me to the next argument:
Not true. During the Lusankya's escape from Coruscant it traded fire with a Golan battle station - which managed to hold its own without taking any noteworthy damage. The Lusankya ended up jettisoning its repulsor berth to create a shield for its escape.
If a single Golan can hold its own against a Executor-Class, the Spear doesn't really have a chance.
It would take a huge undertaking to infiltrate the GE's capital like that unnoticed, and they'd need incredibly high clearance. Plus I don't think it's a simple on/off switch.
The point is it's going to be a lot more difficult then I think you've given it credit for, which is bound to happen when you're summarizing tactical details, but I felt it worth pointing out.