That still doesn't say it's 50 cetane. Could be 41 or 42 for all we know. (I'm assuming the GTL component is left out of our Canadian V-Power diesel so no 1-2 points of cetane increase there)
I also love how ambiguous his reply is saying it varies due to many factors. This tells me they have ZERO clue what the actual cetane value truly is. We'd need someone to take a sample and run a test.