Um.. that may be true, but in most countries buying stolen goods regardless of whether you're being a good Samaritan, is illegal. It's a bit like finding weed growing in your garden, you're not legally allowed to touch it (possession), cut it down (cultivation) or heaven forbid burn it even if you think that you're just getting rid of it you have to go to the police first. We don't know if Apple has pushed for the search warrant, as far as I can tell Apple are being remarkably civil about the whole thing (given what an absolute tits up they've made of it). This is more likely to be a separate police investigation.
What I don't get is that they guy called Apple who fair enough had no idea what he was on about, but the fact that he lived 20 miles from Cupertino. Why didn't he just go to Apple HQ and deliver it in person or at least try? Others have mentioned that the Apple employee's Facebook account was active on the phone when he found it - he didn't try to go to see the guy to sort it out or even email him. Either way, even if he should have sat it out until Apple listened, the right way of going about it is *not* flogging it on eBay. He should have sent a photo of the device to Apple customer support (which they claim he didn't, he just asked them) or one of the higher up execs which would have sorted this out. But anyway, the list could go on, there were a myriad things he could have tried before selling it.
My opinion? They want to be absolutely sure that all the evidence about the phone is destroyed and that Chen hasn't got any "secret" information that he's holding back.
Were Gizmodo right to publish all that information? Maybe. They ran a very though provoking article about it and I agree that Apple shouldn't have total control over how their products are reported on. However, this was a fiasco that could have been avoided by the person who found it taking a little more effort (yes he tried, but IMO he didn't try hard enough).