Remember that Donald grew up in Norman Vincent Peale's church, which he attended for fifty years. It was and is about the Power of Positive Thinking. Plus, what would Scalice's family think if Donald gave an iffy statement? I think it's the president's job to buck up the troops at a time like this.
The President didn’t make this up on ‘positive thinking’. He was being fed real-time reports on the situation and was told as the media reported that Scalise was in good shape and expected to survive.
There’s a background on Sava that is not good. As long as he was dealing with low-level nobodies, he could do his dirty work. When he encounters a high-profile person, he can still get away with dirty deeds. But when the President sent over a WH Physician to peer into the situation, Sava suddenly backs off.
That’s all I will say for now.