Sounds like you got really lucky against some prepared pro Landy thives. They had probably scouted yours out beforehand and came prepared.
The cops probably wanted to recover it because Crime Scene Investigators will normally only examine a vehicle undercover in a secure location, ie the contracted recovery operators warehouse. This lot sound like they would have been gloved and face covered though so CSI would be pretty redundant.
Your best bet would be if they found blood from a scuffed knuckle or head bang. Lord knows I've had plenty of them removing propshafts.
I park mine on the high side of a narrow driveway with my wife's car behind it, steering locked on full, with Disklok isolator tracker etc all deployed.
It makes it a pretty tough job to get out and means if it were attacked like yours they would have to steer hers and mine (assuming both vehicles were steerable) backwards then down hill. Very, very difficult to do I've tried it.
Of course it's nigh on impossible to completely guard against theft, especially if they are prepared to tow or truck it away.