Stolen bikes

I heard another story today about alleged 'skeleton key' use when stealing a bike locked with a popular choice of lock (a good one). The person in question had locked his bike to his friend's with her lock and when they returned, her bike was still locked up there but his was gone. It's unlikely that they cut through his frame, as his bike was reassuringly expensive.

These stories have been around for years but I've never seen any clear proof of them, and it is possible that the lock may simply have been picked; one (self-alleged) witness of such a picking I once met claimed that it looked just like someone unlocking a lock.

It takes skill and there probably aren't too many thieves around who use this technique, but it is one of the oldest ways of defeating locks, after all.

Picking a single sided key barrel lock isn't hard in the slightest but doing it quickly takes practice , which lock was it out of interest ?