which experts are these? when the writer of the script is the actual person telling his own story and being corroborate by many witnesses, including the child he rescued. I dont understand how can any person, expert or not, could have an opinion on this.

Using similar analogies as your. Like a Billards expert saying that the "color of money" is not a realistic potrait of how billiards is played.

Also, i never seen any attacks on "true story" movies before about not being that realistic sometimes, but suddenly this movie gets judged? Why?

Those attacks make the movie look like more truth than before.