Samantha Fuentes, who was shot in both legs during the Parkland assault, said she had felt no reassurance during a phone call from the president to her hospital room last week.

“He said he heard that I was a big fan of his, and then he said, ‘I’m a big fan of yours too.’ I’m pretty sure he made that up,” she said in an interview after being discharged from the hospital. “Talking to the president, I’ve never been so unimpressed by a person in my life. He didn’t make me feel better in the slightest.”

Ms. Fuentes, who was left with a piece of shrapnel lodged behind her right eye, said Mr. Trump had called the gunman a “sick puppy” and said “‘oh boy, oh boy, oh boy,’ like, seven times.”

The account of the call was reminiscent of the last time Mr. Trump drew public scrutiny for his reaction to a tragedy, with his private condolence call to Myeshia Johnson, the widow of Sgt. La David T. Johnson, one of four American soldiers killed in an attack in Niger.

In that case, in October, Ms. Johnson said she had been deeply offended by Mr. Trump’s words and tone, saying that he had not referred to her husband by name, calling him only “your guy,” and had upset her by saying that Mr. Johnson “knew what he signed up for, but it hurts anyway.”

Mr. Trump quickly lashed out on Twitter, saying he had spoken respectfully to the widow.

Colleagues said Mr. Trump’s notes on Wednesday were written by Hope Hicks, his communications director and longtime aide, who had briefed the president along with Sarah Huckabee Sanders, the press secretary, before he attended the session.

The president’s aides had been well aware that he might confront an emotional and potentially volatile situation when he sat down with grief-stricken parents and students, as well as others who had been living with loss for years or even decades. They decided to allow news cameras to capture the entire session anyway.