First, you presume there's a trade secret. There's no indication that is correct; all I see is a new soon-to-be-sold product that Apple intentionally let off of its campus and into the wild.
Second, you presume Gawker criminally misappropriated or otherwise misused the trade secret. Gawker bought a lost phone. Did they have a duty under California law to seek out its owner? Possibly -- but that's an entirely different question from if they criminally violated trade secrets laws. There's no indication that Gawker had any duty at all to protect Apple's secrets; it's not like Gawker is an employee at Apple. You can't just say that, because a person committed a lesser crime, they necessarily committed all greater conceivable crimes. Same goes for the person who found and sold the phone.
Third, you presume the government had probable cause to believe that each of the items seized from Chen had information relating to a crime. Two problems with that: (a) as noted above, it's unclear a crime even was committed and (b) the warrant was patently overbroad, and its doubtful the government had more in mind than a fishing expedition. That's a plain violation of the Fourth Amendment.
Fourth, where's the fire? There's no on-going crime here. There's no criminal enterprise. There's an isolated, public incident. So why the high priority? Why the extremely aggressive measures of seizing all of a journalists' computers?
Compare and contrast that situation to one of the cases listed on the DOJ website you linked to:
"In support of his plea, Mitchell acknowledged that on September 5, 2007, he emailed much of the contents of a DuPont proprietary spreadsheet document entitled “Denier Economics” to an official with Kolon. “Denier” is a term used to describe the weight per unit length (linear density) of a continuous filament or yarn. The Denier Economics spreadsheet contained highly sensitive business trade secret information related to DuPont’s production capacity for Kevlar® yarn in a variety of denier types. Included in the information for each denier type were specific figures relating to annual production, unit capacity, spin speeds, and several factors relating to line efficiency (such as percentage yield and percentage up time). The Denier Economics spreadsheet was closely held and distributed to a small number of DuPont personnel on a need-to-know basis only."
Now that's a trade secret, and it's a clear misappropriation of it by someone with a duty to keep it secret.
And what did the DOJ do there? Did they start seizing the property of third parties covered by shield laws?
No. They slowly started building a case.
The exact opposite of what REACT did here.
Shoot first, ask later, for high profile crimes is not just the wrong approach, it's unconstitutional and inappropriate. And it demands an explanation.