This AP account is not accurate.

In 2016 Khan stated that Londoners had to get used to Islamic terrorism because there really wasn't really much that could be done about it.

Contrast Khan's statements about Islamic terrorists with Theresa May's.  She is clear that "enough is enough."

Khan, by contrast, does see either Sharia Law or Islamic extremism as a problem for London.

In sum, Trump's critique of Khan was spot on.