Is it safe to retract a zoom lens by pushing on the lens hood instead of turning the zoom ring?

We are presumably talking about a purely mechanically linked zoom here. The lens groups and shafts run in threaded gear tracks. What you are doing here is reversing the operation, pushing a shaft to make its gear track turn and move all of the other groups/gears in turn. The respective mechanical elements and tracks are not designed to work this way round: it's a bit like trying to turn a screw by pushing a nut on it. In theory, that's in some way an invertible operation but in practice you are not going to do your threads a favor.

In the best case, you'll put much more of a load than usual on the respective pins moving the lens shaft, making the positioning of it and its affixed elements/groups lose precision in a smaller amount of time than the lens has been designed for.

Few compact cameras contain mechanically linked zoom: making the comparatively small components reliably survive regular human operation and irregular human operation comes at a cost in complexity and materials that may be more than a zoom motor actually weighs in at.

In short: just seems like a bad idea asking for trouble along the road.