> But there is no rule that says someone must be an employee of an agency to assist in shutting down the agency under delegated authority from the cabinet official that oversees the agency.
So the delegated authority from Rubio is what made it legal for him to shut things down? He wasn't appointed and delegated until March 18th. He started there on January 28th. Sometime around January 30th he participated in ordering the acting administrator to shut down communications systems and terminate top officials. He was working there for 7 weeks as a non-employee, non-appointee, non-delegate, forcing the hand of the administrator who is supposed to be Senate-confirmed.
Even if you fall back on his detailing from GSA, it's dated Feb 14th and is "contingent upon the Detailee’s successful adjudication and receipt of... pre-employment screening required by USAID" -- the screening he did not complete.
Do you consider shutting down the agency a special activity, distinct from working within it at any other time? It seems a strange qualification to put on. Are the requirements for staffing looser if the official intends to close the agency?
> if he was transferred within the department from vice into homicide
Then he'd still be an authorized police officer, I presume. You argued based on explicitly delegated authority from the USAID administrator or cabinet official, not that being a GSA employee meant he could go to any agency without further authority. Per above, he wasn't immediately given the delegated authority, and even his detailing seems on shaky grounds.
> doing a search is a potential impingement on individual rights
Well, yes, but it's also explicitly in the law that there are procedures to authorize a search, same as the law says there are procedures to change staff, spend or not spend funds, or shut down an agency. If anything, the thousands of fired USAID employees and tens of thousands of USAID beneficiaries had their individual rights impinged by the "internal reorganization" (but I admit, probably not Constitutionally-guaranteed rights.)
Why do 2/3 of the law professors quoted say he should have been Senate-confirmed? Maybe they're biased or were fed the story and reacted without much research. It's at least a flaw of the article that it doesn't clearly explain why a COO would need to be confirmed. Maybe the professors consider Rubio's delegation to be making Lewin the de facto administrator without the required confirmation.
Anyway, he probably became fully authorized on March 18th. I don't know if he actually succeeded at anything notable before then, but he was trying to shut things down and coerce the legal administrator while, at best, a provisional detailee. I think that should be as disturbingly sloppy as sending out a police officer with inadequate legal certification on file, or performing a search with only an unrecorded verbal assent from a judge. In some hand-wavy way, any of these cases are "authorized" (e.g. I presume Rubio or Trump would have approved of anything he did), but we should expect a stricter documented standard in full compliance with best-practice procedures. For 7 weeks he was below even your bar of "delegated authority from the cabinet official", let alone some experts' claims that he should have been confirmed.
P.S. I think rayiner doesn't oppose Jack Smith's appointment, but I assume anyone else defending this also supports Smith's appointment and opposes the court meddling with it... if a president doesn't need anyone's permission to staff his branch however he likes.