The Chelsea and England footballer had been accused of a racially aggravated public order offence after allegedly calling Ferdinand a "f**king black c**t" during a Premier League match last October.
Tweeting directly from court,
"[The] issue is whether Mr Terry uttered the words f**king black c**t as an insult. If he did, the offence is made out."
He continued: "Overall I found Anton Ferdinand to be a believable witness on the central issue.
"[The] prosecution has built a strong case. [The] question is whether the defence has established a doubt."
Riddle added: "It is impossible to be sure exactly what were the words spoken by John Terry at the relevant time.
"It is a crucial fact that nobody has given evidence about what Mr Terry said or how he said it. John Terry's account has been subject to the most thorough questioning. Nobody has been able to prove he is lying."
The chief magistrate concluded that it was indeed possible that Terry's words were not meant as an insult and added that "the only verdict the court can record is not guilty".
Chief Crown Prosecutor for London Alison Saunders said in a statement: "The very serious allegation at the heart of this case was one of racial abuse. It was our view that this was not 'banter' on the football pitch and that the allegation should be judged by a court.
"The Chief Magistrate agreed that Mr Terry had a case to answer, but having heard all of the evidence he acquitted Mr Terry of a racially aggravated offence. That is justice being done and we respect the Chief Magistrate's decision."