A good cautionary tale mate, and one that people will be wise to listen to. Just because someone is sat in a tractor or resident in a farmhouse doesn't mean they are the landowner, so like you say, always double check. there's a guy local to me who has youtube'd himself on a plot of land which I know for a fact is owned by the Council, but he's told me he has permission from the farmer who grazes cattle on there so it's okay??? I don't think so, and if he gets caught I think he could be in a lot of trouble!!
Hope it works out ok with the actual landowners mate, sounds like the bridges are not completely burnt.