When your employer pays you overtime to do something that you normally would not do, is that a bribe? Or is it a fair trade: their money for your time?
There were a lot of things wrong with what you did there, not just the mistake of grabbing his ear. Chasing him, for starts. Then continuing to pursue after he's started hiding, and cornering him. And grabbing the phone back while it's still in his sphere of influence (right under him). The main problem with the dog that I'm seeing here is lack of bite inhibition--a dog with good bite inhibition can "bite" when they feel threatened but not actually break the skin or draw blood. They can soften their bite so it's more just a symbolic response than an actual attack.
The "trading" game to teach a "drop it" command is not a bribe if you do it right. Meaning, it's only a bribe if you continue to dangle treats in front of his nose in order to get him to drop something. If he willingly drops something and you immediately jump up and make a big fuss and go get him a goodie, that's not a bribe, it's a reward. And once the behavior gets a good track record, you don't have to reward every single time--you keep the dog guessing, is this the time I'll get my reward? And what will the reward be if I do? Will it be something awesome? It might be! Or maybe it will be something pretty good. I don't know! Let me drop it and see what happens! The most reliable behaviors are those taught with this kind of variable schedule of rewards (meaning, both the kind of reward the dog gets varies, and whether or not he gets a reward also varies).
Do you leave a lot of stuff sitting around that he's allowed to have--his toys and such? Because if you do he's not going to automatically know that picking up this, this and this is okay, but picking up that and that and that other thing is bad. The way to deal with that is to either pick up everything that is his and teach that NOTHING goes into the mouth, ever at any time, unless directly given by you. Or, you can teach the "drop it" command using rewards and if he picks something up by mistake that is not his to have, you say "drop it", he drops it willingly and happily.
I don't have a big problem with my dogs resource guarding from me, but it has happened once or twice and since I have very large dogs it is automatic for me to not even think about having a confrontation with them. I would loose. When having a confrontation like that, I can't think about it as me "winning" or "scoring one off the dog" because frankly I wouldn't win. I try to defuse the situation and make it in to a win-win. Last time Conrad had a wild hair and tried guarding a bone from me, I stopped trying to go for it, stepped back and gave him his command to go to his kennel--a command that is very frequently rewarded by treats and goodies, so it has very positive associations. He immediately dropped the bone and kenneled up, whereupon I gave him a treat. Win-win. I got the bone safely, he got a little reward for doing something easy that he knows how to do and enjoys doing. That's not a moment where I was going to be able to teach him anything--teaching happens in situations where you purposefully set the dog up for success by making it easy and very rewarding. That was just a defuse, to get Conrad out of his state of mind of wanting to guard and give him another task to complete that got him away from the bone safely and without any physical confrontation.
Try getting your hands on a copy of "MINE!" by Jean Donaldson. It's a short little booklet that goes over several protocols for dealing with resource guarding and teaching dogs to surrender their treasures willingly without confrontation.
