The first episode had to be re-filmed when Mike Stoklasa and Jay Bauman decided they should have a reason for being in Mr Plinkett's house and came up with the idea of VCR Repair Men which continues throughout the series. (Drive Angry and The Adjustment Bureau (2011))
The Plinkett character in Half in The Bag, played by Rich Evans, is a different character entirely to the Plinkett in the Plinkett Reviews, played by Mike Stoklasa. This was clarified in an update video called "Harry's Next Review" where they joked about the continuity. This explains the massive contrast between the two characters.
While Rich Evans plays Mr. Plinkett in this series, Mike Stoklasa's Mr. Plinkett can be heard in the intros to every episode.