In kedushah, in hazarat ha-shatz, when the congregation has finished saying 'Kadosh kadosh kadosh...' and it's time for the shliah tzibbur to repeat the line out loud, it seems like the practice is for him to begin one word in. I.e., he must have said the first 'kadosh' silently already. Why is this?
I learnt once (sorry, no sources) that the Kedushah is responsive - Shatz and Kahal, but the Shatz is himself part of the Kahal, so in order not to separate himself from the Kahal he starts with them and prolongs the first word until they have quietened down. This is particularly important with Shema in Musaf. Alternatively the Shatz can say the response together with the Kahal and then carry straight on with the next section.