Was there a Saudi suspect in the Texas fertilizer plant explosion?

I’m looking at this BS on FB. And there is some argument raging that there was a “Saudi suspect,” says A.
“No, there was a Saudi witness,” says B.
“A Saudi “witness’ would not have invoked diplomatic immunity and be flown home,” Says A.

I want to say something because it’s obviously anti-Obama BS, but I don’t know what to say.