Surviving the apocalypse

We've had the hedges cut in the lane.  Our friendly neighbourhood hedgecutter always phones in August, hoping to persuade us to have them cut then, probably because farmers can't cut theirs yet, and he's itching for something to do, but I insist on hanging on into October, so that the birds can make the most of the berries.  The hedges really do need trimming much earlier.  The summer growth of grass is just so much posturing, but by the end of August the brambles have decided to migrate, and start shooting out across the lane in thick and vicious tentacles, and the nettles and goosegrass, which have been lurching upwards quietly into the hedgerow all summer, suddenly decide they've had enough and flop over.  So it helps, in September, to tackle the lane with a machete.  But the hedgecutter, when he comes, doesn't just trim back the weeds.  He rips, mangles, snaps and savages his way through the hawthorn and ash and holly and blackthorn and elder so thoroughly the hedge is trimmed back to bleached bones.  Suddenly I can see the sky again.  If the birds haven't had their fill of the hips and haws, the elderberries and holly by now, tough.
What is odd though, now that I look more closely, is that although most of the leaves have been whipped off, along with every shred of new woody growth, most of the berries seem to have survived the cutting.  It's surprising enough with sturdy waxy little buggers like the rose hips or the holly berries, but how on earth did the bryony survive the thrashing and thwacking of the hedgecutter?  It is festooned along the shattered branches, in great swathes of blood bubbles, bursting with juice. The blackberries have gone, splattered into oblivion, but the bryony survives as if nothing has happened. I want to know how.