That's really not for you to question. But the answer is that you did mention in your application that you would ask to take items from his chests in a few months if he didn't return, while Radio stated that he would leave them be and preserve the plot in the state in which it was left. That's the key difference right there.
The thing is, we are never really happy about people buying plots just to benefit from the contents of their chests unless there was a known close relationship between the players beforehand - and I'm not talking just a 'same guild and toured his plots' relationship. So when an old vet's home plots disband, we'll either refuse all applications for a few months until it is clear that they are not returning, or we will approve one that is for preservation only. That's why Radio's was approved.
I would expect on that basis that Radio would have left the plot untouched and happily sell it back to Diamond_boss for 10k + tax. If there was an issue there and Radio wasn't willing to sell the plot back, then that's where Diamond_boss should ask staff to chat with Radio because approval was only given for preservation - and now that the original owner has returned, there's no reason to keep 'preserving' it rather than selling it back to him.
monkeychunks wrote:He literally just told me he could legally loot them if he wanted to in a private chat...
Nope. That wasn't the basis of his application and approval, as I've made clear above. He would need to contact staff if he wanted to change anything, and approval likely wouldn't be given.