I dont know……only because the knife was buried in a very different part of the woods than the Graham/Gold spade scene (very possible he went & dug it up & buried elsewhere I suppose)…… However In the final eps promo, you see Pino??? looking into a big tree (as the camera pulls up & away from ground), then said tree has a part of it blasting out/open & Pino? being thrown off his feet backwards (wide shot).
I think that the tree where Gold was digging looks VERY similar to the blasting open tree- both even have holes/gaps in them & in the pulling up frame of the promo you can see saplings & foliage around the main blasty/hole tree just like the one Gold was digging next to….. Im thinking Gold has ‘planted’ a bunch of stuff he doesnt want others knowing about.