Thanks for the replies everyone. I think the gravel is too high, but hopefully being gravel there won't be too much splash back as conney says. The patio replaces some decking that was there before and until now there haven't been any damp issues; I guess time will tell.
Does the patio in this picture look ok? There's a strip of gravel between the slabs and the wall, but I think this is above the DPC; anything to be concerned about? I'm not sure where the DPC is tbh, or if having gravel above it is ok.