I don't know for sure, but given the privacy laws of Canada, he could have very well been arrested without public knowledge, since it appears that RCMP nor the Canadian Border Service are allowed to discuss it.
But I have to believe that the news would have leaked, from say, some clerk in the office that wants to break the news. So I don't know about an arrest. However, when you are talking the possibility of criminal charges being filed, you are talking about booking procedures. I know in several investigations in which I was the investigating officer, we let the defendants come in voluntarily for booking purposes.
That's what may have been done here for courtesy purposes.
DISCLAIMER: Keep in mind this is speculation, and discussed in a general manner and as a response to a poster's question, and is not libelous in any form to any person or any manner whatsoever.