The 23-year old footballer, now playing for Wolverhampton Wanderers after a spell on loan with Hibernian last season, had been charged with stealing water and juice from the store in Meadow Place Road in Edinburgh on January 26 this year, assaulting an employee by attempting to punch him and to committing a breach of the peace.
However, at Edinburgh's Justice of the Peace Court, Fiscal Depute Gerard Druggan, accepted not guilty pleas to the theft and assault charges.
Griffiths admitted shouting and swearing at staff and struggling with them.
Defence solicitor Kathleen More told the court that on the day in question Griffiths had been due to catch a Hibs team bus to travel to Aberdeen at 3pm.
"He went into the store at 2.45pm and collected water and juice for the journey. He purchased these items and then made to leave the shop," she said.
"As a result of a misunderstanding, when he tried to leave the shop he was stopped by a member of security. Fearing he was going to miss the bus, he over-reacted."
Justice Robin Vaughan said he accepted there had been a large degree of misunderstanding, but he added: "That does not excuse you losing your temper, swearing and struggling with the shop staff."
He fined Griffiths, who has played for the national team twice, £100 to be paid by September 19.