The video shows you already partway into the bus lane as you follow the bus. Only part of the car need be in the bus lane for a contravention. Certainly it doesn't look like de minimis would apply
However, looking on GSV to see where this is, I would be strongly tempted to appeal on 'vague locus', because Hagley Road West is very long and the PCN does not sufficiently describe the location of the alleged contravention.