I originally thought I wasn't getting the bite-point right on our new (2nd-hand 2005) Mazda 3, but after paying more attention it's clear that when up-shifting, the engine revs often blip up about 1000 *after* I've totally released the clutch pedal, for a second or so, before dropping back down.

I assumed this meant the clutch was slipping and maybe needed replacing but our mechanic says it's fine, and this is normal on that car. I can't understand how this can happen - once the gear is engaged how can the revs increase so much for a short time *without* it being slip?