At 0.5mg/kg intravenous, there's no way that people wouldn't feel anything. It's not necessarily a "drug trip", but pretty much anybody can tell the difference between that large of a dose of ketamine vs. a saline solution.

For trials in cases like this, it's common to use a group which receives either a smaller dose of the drug or a drug that is intended to mimic some of the subjectively observable side effects.

I do not know what a trip is or is not supposed to be like but it was a very wild sensation.

It's common for those wordings to be used because often it literally is a handing over of drugs you're talking about - with sickness you're more likely to talk about the moment a medical person said to start using a drug than to tell people about the actual use because it's usually more interesting.