They aren't "two different things." I think you mean that hydroxychloroquine is derived from chloroquine and are different chemicals. They are very similar and are used for the same indications. But the woman said later when interviewed that she got the idea from hearing the president speak about the drug. Trump did mention chloroquine (along with hydroxychloroquine) as being the cure. The husband thought that taking a teaspoonful of the tank cleaner would be a good idea. Turns out that a teaspoonful of the tank cleaner contained a lethal dose of the drug.
So did Trump tell these people to consume aquarium cleaner and is, thus, directly at fault? No. Are these people idiots? Yes. Should Trump, with his laymen at best knowledge of pharmacology, go on stage and proclaim that a drug that has very little evidence from a very small case study is a miracle cure? No, because stupid people will do things like this.
If nothing else the coronavirus calamity has shown one thing to me. It's that an alarmingly high percentage of humans will talk out of their ass about subjects they know absolutely nothing about with such conviction that they actually know what they are talking about. The media does it (Fox News, MSNBC, and, to a lesser extent, the non crazy media). The president does it. Random idiots on Twitter do it.
I wish everyone would just shut the hell up and listen to experts. It's classic Dunning-Kruger effect in action.
And everyone seems to be permanently stuck on naively confident 24/7.
Edit: rewrote the first paragraph to lower confusion as to what I meant.