Sorry factor no idea of any link - I just remember it from when I did Criminal Practice and Procedure. Generally, it will be the officer in the case who makes the decision ie whether to charge or summons. Very often criminal proceedings are started by way of charge but in this case it looks as if the def has been interviewed under caution and then left - thereafter the OIC has taken pre charge advice and decided not to recall him to the police station but simply to issue a summons. At the magistrates court the Def should be entitled to see duty (subject to meeting the requirements of legal aid) but in any event, this will be committed to the Crown Court at which point legal aid will definitely be granted.
Although there has not been a "charge" per se Calvados, the information can still be laid in front of the magistrates and then your friend has to answer the charge which is then "put" to him and to which he pleads guilty or not guilty.
A good example is driving without due care and attention. You are often not arrested or charged but are told you will be "reported". The next thing you get is a summons requiring you to answer the charge at the magistrates court.
Sara3 may be able to assist since similar happens with benefit fraud. You are not arrested, nor charged, but interviewed under caution and then summoned to the court.