You have to jump to page 43 for the policies on discretion as what comes before are reasons why a contravention has not occurred.
Havering are more generous in discretion policy MC3 than many other councils in London (and an Adjudicator would probably find against you).
Policy MC12 isn't fair and reasonable. You park and the car behind you bumps you forward partly into the next space. No incontrovertible evidence is available (you don't photograph your car every time you leave it although Mr Musatrd does if the bay has no sign).
MC15/16 & 17 are all examples of the fettering of discretion as Havering will never cancel, that cannot be within the sprit of exercising discretion.
MC27 - Mr Mustard is bemused. The motorist is in jail and the PCN process will just plough on? How is the motorist to visit site to take photographs of something that is wrong with signs or lines.
MC32 is wrong. If you are dropping your 5 year old at school and the nearest you can reasonably park is a double yellow line 400m away then you can leave your car to walk with your child to school, it would be gross neglect to send them on their own.
MC44 is a good thought. Havering Council meaning is if you are following an ambulance to the hospital as it has a member of your family inside, not that you are closely following the ambulance whose blue lights are parting the traffic for you! (don't do that).
On a separate note, pages 89-91 about accepting instalments are interesting. Mr Mustard doesn't think they are entirely fair but this may be an enquiry he makes of every other London Borough one day.