"The protesters blocked the vehicle entrance to the restaurant, creating health and safety concerns for both themselves and customers, as cars attempting to enter the restaurant were faced with either running into protesters or reversing back into oncoming traffic.
"This resulted in a minor car accident."
Ms Bartlett said it was not appropriate to comment on the allegation that a customer's vehicle hit protesters, saying the matter was now with police.
Senior Sergeant Brian Benn of Dunedin police confirmed a complaint concerning a motorist had been received.
Inquiries were continuing.
The protest had caused "havoc" on the one-way system north, with vehicles banking up, causing "them to slam their brakes on ... so it was a wee bit of a shemozzle", he said.
The protesters later agreed to move to a safer location before leaving just after 6pm, he said.
The protests - dubbed "McStrikes" - began peacefully outside the city's central George St branch on Saturday.
They were repeated again yesterday, with eight placard-waving picketers blocking the drive-through at the Andersons Bay outlet from noon.
Dozens of motorists headed towards the store's drive-through before opting to either park or leave the outlet.
Ms Butcher said the "McStrikes" would have impacted on the fast food giant.
"We are going to keep on doing it until they give our members what they want. I think out of all the ones we have held around New Zealand this one would have been the most beneficial in terms of financial loss."
The North Dunedin protest was the latest "McStrike" to end in controversy - an incident in Christchurch last week led to an allegation of assault.
