throw...for a loop

東野圭吾の小説 "New Comer" を読んでいます。

'It threw our forensics guys for a loop. They were like, what's this all about? I was pretty surprised when they told me that one of the cakes was spiked with wasabi. Unbelievable!'

"threw our forensics guys for a loop" は 7/20/2009に取り上げた knock/throw you for a loop ですね。