Does Trump have a case?

The current Lord Mayor of London, England is one Sadiq Khan, a Pakistani.

I have noticed that he is very quick in his comments about terrorist attacks. 

They tend to mollify the seriousness of the attack to becalm the nerves of Londoners. And I can understand that.

In turn, The Donald has this response:

http://timesofindia.indiatimes.com/world/us/trump-criticizes-londons-mayor-again/articleshow/59004403.cms

The question is this:

Do you think our Donald 

is too harsh on poor Sadiq?