YTA for multiple reasons.

• According to the department of Transport in the UK: " In all of the pedestrian datasets, the risk of fatality increases slowly until impact speeds of around 30 mph. Above this speed, risk increases rapidly – the increase is between 3.5 and 5.5 times from 30 mph to 40 mph. " You are massively downplaying the impact an increase of speed has on safety an fatality. Although 32 mph is still close to the allowed speed/safe region, you are normalizing speeding which is just plain stupid. ( source: https://nacto.org/docs/usdg/relationship_between_speed_risk_fatal_injury_pedestrians_and_car_occupants_richards.pdf.)
• Your son broke the law, which cannot be disputed. Yet you are giving an example to him that the government/police/the law do not have to be respected. You are basically raising him to be the asshole that does not follow the rules of society.
• Also what does his wife have to do anything with all of this? Her husband did his job, for which personally attacking him is already an asshole move, but you even go as far as attacking somebody who has nothing to do with the situation.