LOL! When a private company or individual acts as an agent of any law enforcement agency, then the government is also an actor.
if Liberty had called up the FBI and volunteered the information, then you'd have a point. But when they were asked for the code and willingly handed it over without a subpoena, they were acting in the same capacity as any other officer helping to execute a warrant on the subject's home.
Ever watch shows like Law & Order? i've seen many movies, TV shows and episodes in which a cop talked a third party into doing what they could not do themselves -- like searching an apartment the third party is the maintenance guy or landlord for. The evidence gets thrown out because the third party was only looking for the evidence at the request of the police. That's all it takes to become an agent of the government. And if the agent violates someone's constitutional rights, the government is responsible.
The truth lies in the weeds. If the FBI called up Liberty safe and said, please help us break into the safe, then yes, they would be considered acting as an agent of the government. If the FBI asked if there is a backdoor code to unlock a safe and Liberty Safe provided that information then it would be hard to make the case that Liberty Safe is acting as an agent of the government. Between that those two ends is lots of gray area.
Regardless, even if Liberty Safe physically participated in the opening of the safe, at the direction of the FBI, and would therefore be considered agents of the government, Liberty Safe would not be guilty of an improper search. The results of the search might get tossed out as fruits of the poisonous tree of course.
According to the video by Brandon Hererra there was a search warrant to look into the safe. Furthermore he stated that according to Liberty Safe's statement, they received proof that the FBI had a valid search warrant. So at this point, I don't see much of a legal issue. If the FBI did the traditional thing and hired a locksmith, they would not need an extra subpoena to order the locksmith to do his thing. Yes the locksmith would be acting as an agent of the government but the search is legal if there is a warrant. The difference here is that they asked the company about a back door means of opening the safe and the company provided them with it. Now if the FBI asked LS for the specific code to Flapp's safe and LS provided it, you could argue that it was your personal information and that you had an expectation of privacy to said information. However if LS just had a master key or master code that worked on all safes you would have a hard time claiming that code as your personal information and therefore subject to an additional search warrant.