"Authorities at the Hutto detention centre have acknowledged holding 170 children there." Why blame Canada for this?

Canada did not grant them asylum the first time. They were trying to apply a second time but didn't reach Canada. If Canada intervenes, it will be on humanitarian grounds, not because they are in any way obligated.

What excuse does the U.S. have? They were detained and put in detention by the U.S., not Canada.

btw - I do care about the plight of Iranian women but the plight of this woman in one circumstance does not apply to most. Like I said, it makes a good movie.