I think it is. Blunt blades with speed can cut.
[video=youtube;ZR9k23U-P10]https://www.youtube.com/watch?v=ZR9k23U-P10[/video]
I doubt that it is, because wrist bones and tendons are quite hard to cut without a rigid bracing position, or a stop surface to cut against: Even with a perfectly sharp blade, without a rigid backing stop, the hand would never have come off cleanly without at least a strip of flesh hanging on to it...
Even then, a hugely powerful, full swing blow would have been required.
They also added a little of obvious CGI blood spurting, which would only have been visible as dripping straight down...
They take their notion of what would visually happen from the "Walking Dead"...
And no, blunt will not cut flesh, not even close...
Gaston