

Well, for merely commissioners that moved from the commission to those positions, the first example that comes to my mind is the head of the EU Commission during the 2008 Crash and it’s aftermath, who went to Goldman Sachs afterwards and is still there today as a non-executive president.
During his time in the Commission they were very pro-Finance in the way they handled the aftermath of the Crash with him personally pushing frequently for measures were EU money was used to unconditionally helped the interests of large Financial Industry companies, and Goldman Sachs is one of the largest companies and massively benefited from, amongst other things, near-defaulting Greek Treasuries being bought from the private sector by the EU, which subsequently forced the Greeks into Austerity to as much as possible pay those Treasuries.
There’s even a scandal with him were, whilst working at Goldman Sachs, he broke the EU rules on lobbying by using his access card to EU buildings - which he was entitled to have as an ex-Head of the Commission - to simply enter into those buildings and waltz over to the offices of sitting EU officials to lobby for Goldman Sachs. The EU ended up revoking his access privileges, the first and only time that has happened for an ex-EU Commissioner.

I personally know a person who was charged and convicted of the Crime of Libel (in what for my country was an incredibly speedy legal process) for accusing a local politician of Corruption.
Curiously, about a decade later said politician was convicted for Corruption. Lets just say it only happened because that Libel conviction really pissed of that person who had time, brains and no fear of their professional life being affected, so they worked tirelessly behind the curtains to push an earlier report into “irregularities” in his City Hall all the way into and as a case against him, including digging evidence even from abroad and having to threaten with exposure in the Press at least 3 public prosecutors who on different occasions were quietly holding the case so that it didn’t get to court before the deadlines for prosecution expired (and even then that politician actually got away with a number of crimes because the deadlines for prosecution did expired for those). In fact that was the first politician ever in my country convicted of Corruption.
Libel having been made a Crime in my country (which is quite unusual in the World) was done exactly so that people can be punished for openly accusing the powerful of malfeasance without the powerful having to bare the costs for a civil court case and actually prove damages (so it mainly helps politicians in the big parties who have the connections to get the local Public Prosecutions Office to take the case to court) and that’s exactly how it has been used.
By an amazing coincidence my country is one of the most corrupt countries in Europe and last I checked was the one most behind in implementing the EU advised anti-Corruption measures.