Uhg. No. Well, yes in the most literal sense: if it is recorded there is a record of it, BUT if you ask a journalist to keep something off the record and they agree, then whatever you then disclose is usually not published of otherwise made public. See: journalists like having good relationships with their sources and if the journalist gets a reputation for saying something is off the record and then writing about it, people stop talking to them. OTH, if a journalist happens to see something heinous, you probably won't be able to retroactively get them to let it slide -- but in that case the journalist isn't betraying a trust.

TLDR; You can't force a journalist keep something off the record, but if you ask in advance, they might agree.