Overdosing is not a crime, it's not even the job of the Police to help, and possession of drugs is being ignored by most forces because an arrest takes two officers off frontline services for 4 hours, when it will most likely result in a caution.
Also if someone is overdosing, they are probably possessing.
People should do it at home or somewhere else, not on the streets. I don't care if someone is consuming inside their home.
This unevidenced claim is probably nonsense in any case, no police officer would simply walk by. They may very well walk by and talk into their radio to summon the right kind of help, or they may be responding to a higher priority call.
Just because your mate Bob claims they saw something, doesn't mean Bob had any real idea what was going on.
It's like the old saw about a window blind for a hospital ward costing £200, when you can buy one for £20 elsewhere. Thing is the one for £20 doesn't come with a specialised coating that eliminates bacterial or viral spread, or with a bloke that installs it according to the relevant safety regulations, or the supervisor who certifies the installation. It certainly doesn't come with a number you can call to fix the blind if there's a problem with it that includes on site service.
You and I have very different experiences with police officers. Police Officers may walk by someone overdosing is hardly a claim that needs any evidence in my experience because it's so widely understood to be true.
"Here" being "Hungary".