Well Grant apparently has been in Dubai!
A_Galadari: "We just took a picture with a celebrity who's name we don't remember" - 25 Nov
"We also had a whole conversation with him and his awesome girlfriend- so sweet!

now let's google his name" - 25 Nov
"His name is Grant Bowler xD" - 25 Nov
I asked him where abouts he saw him and he kindly and quickly replied:
"Mall of the Emirates in Dubai, UAE

"
EDIT: However, I asked if he was filming... but the response I got was:
"no, he wasn't! He was just on vacation with his wife"
Peach has confirmed Grant IS the host... maybe him with his wife is just a cover up? I will double check to see if he did indeed see Grant.