That is for DAMN sure. Same as "off the record" with a reporter.
They are both conning you into saying something that vaguely incriminates you and then you are cooked. The reporter can make you look bad.
The cop can lock you up.
A young relative of mine got conned that way by a SOB cop and ended up in jail for a few hours in a nice orange jumpsuit for obstruction of justice. It was a supposed hit and run with damage on private property. There is no way on earth he could have done what the cop said he did. Physically impossible. But the SOB cop got buddy-buddy with him by having a 'friendly conversation.' Bull$4!t.
The only time the cop is anywhere near your friend is when he thinks some other guy did the deed. If he doesn't have that guy, then YOU are the guy and he is going to do and say anything he can to pin it on you. Guaranteed.
The cop said he knew the kid was guilty and he would go easy on him if he just admitted his guilt. Then then he got him all flustered and twisted his words around, and when the kid said the words close enough to what the cop was looking for, bingo, on go the handcuffs for 'lying' to the cop.
The judge saw through it based on a lot of good photographic evidence.
Now the kid hates cops, even though his uncle was a good one, and he knows now to STFU when they talk to him.
If you're going to violate any of those rules you had better a) know the law as well as the guy in this video does and b) have the same kind of emotional discipline as he demonstrated. Neither one of those things comes easy.