Actually, it is better to communicate first rather than clonk a guy 1000' below you. A turn left/right will take you far enough off track (assuming modern nav systems) to get you away from an airway before you descend.
Once on oxygen, there is no huge rush to descend. In fact you may wish to reduce speed if you have suffered airframe damage (ie cargo door blow-out in a large jet). You might also wish to increase the drag by lowering the gear, to increase your rate of descent.
Many different scenarios that will doubtless excite the PPRUNEry!
Not a snag in the Tiger Moth though!
Mog