As I recall the Borg have always been emphasized to adapt to threats. The Voyager crew modified the Hanson's tech to sneak in, the Borg adapted. SOP. The real thing is that the Borg Queen held back as she was busy trying to seduce Seven of Nine. This is often held as weakening the Borg but Picard in BOBW and Data in First Contact basically got the same treatment.
Survival Instinct never gets complained out, but the Borg drones there are freed, as I recall, by merely being out of range. They certainly manage to "escape" later on, which makes the notion of being a mindless slave somewhat moot. And of course Seven of Nine gets to be the Borg Queen in this episode. This one really does violence to the power of the Borg Collective.