Good opportunity for critical thinking.
"because his father wanted new teeth"
Implied: The father wanted new teeth, so he risked the life of his children over something shallow like dentures.
First step in evaluating the video, is to ask what is the best evidence for determining why someone does something?
The best, and often only, way to determine why someone does something is first hand accounts. "I did this because X". This is why witness testimony in court is admitted. What is generally not admitted in court is someone else's speculation. "He did this because X" i.e. "hearsay"
In this case, the evidence presented is that the aunt, obviously distraught, at a press conference, starts talking about her nephew, the father of the boy in the picture.
She simply stated "he needed money for new teeth". She didn't even say that was the sole reason.
Given the torture, execution, indiscriminate bombing, and general breakdown of the country, one would be hard pressed to simply say, without talking to the man directly, what his ultimate motivation is.
It is quite possible that the man had more than one reason for fleeing with his family.
So basically, one has the word of the guy who wrote the le of a youtube video, based on testimony from a distraught, overwhelmed relative at a press conference.
I require a bit more evidence before determining why the man did it, and stating that with any degree of certainty.
That is critical thinking.
"what evidence is available, what is the best evidence, and is the conclusion supported by that evidence".
In this case, one has a modest amount of evidence, but certainly not conclusive. Unless of course you use confirmation bias.
Use that, and you can state it with some certainty, as long as you don't really care what is real or isn't real.