> ... against the wishes of the landowner and river authority.

...I mean, it originally arrived in the area against the wishes of the landowners at the time as well. The gentleman is simply continuing a long established tradition.

(Seriously, though, aside from the fact he wasn't supposed to be doing what he did where he did it, archaeological information was lost that could have potentially been recovered had the sword been left in situ and a team called to survey it. We really shouldn't be celebrating this.)