This is where he needs to appreciate the responsibilities that come with being the President of the United States when speaking to the public. No, he did not tell people to inject or drink disinfectant, or to stick lights into their lungs. But by talking about it in the way he did (as something that scientists are either looking into, or should look into), some people will come away with the impression that there is something to those things and therefore they're worth trying.
We saw that with how his hydroxyc

roquine rhetoric led to a nationwide shortage of the drug, and in one case an unnecessary death. He never actually told people to take the drug, but the manner in which he talked about it gave a lot of people the impression that it's worth trying. (Sadly now we're finding out int not only doesn't work, in some cases it makes things worse)
At the very least he needs to be much more cautious in what he says, and he needs to be aware that there are a lot of people in this country who hang on his every word and take what he says as gospel truth.