When I had a habit this was often the case. If someone overdosed on a batch people tended to assume it was good stuff. Not necessary for anyone to die and even before narcan most overdoses were survivable. You’ve got to appreciate that unless you have a fairly reliable source, heroin can run the spectrum from pretty decent to completely useless. It’s not a happy feeling when you profoundly need a hit and you’ve spent your last money on stuff that doesn’t work at all. After this has happened a few times you’ll jump at the word of someone having strong stuff.