When Six60 began playing they were near the front and five minutes into the set another fight broke out.
She said it was between about seven or eight people, but was hard to tell as people tried to intervene and break it up.
"A girl got involved and they dragged her to the ground and I don't think she was to do with any of that party, I think people were just trying to jump in and stop it."
The same people who appeared to be initiating that fight then began fighting with another group of people.
"They were absolutely drunk as anything; people were pushing through and people were trying to stop people coming through.
"It just got heightened and we didn't feel safe at all where we were stood."
She said there was "definitely" a gang presence and she saw gang signs and people shouting to each other through the crowd.
Other comments on social media shared positive experiences of the night.
"Best concert, best concert area just an awesome night, come back," one said.
"We had a great night I didn't see any other people being stupid. We had a blast. Best concert ever," another person said.
De Jager said "there were a small number of incidents during the concert" but a hi-tech crowd monitoring system normally reserved for use in large stadiums, combined with "high numbers" of security and police meant "any issues were quickly addressed".
"There will always be a small numbers of badly behaved people within a concert environment, our job is to ensure they don't ruin the otherwise enjoyable concert experience for others."
He said police were "incredibly supportive throughout the show".
He said until they complete the post-review event there isn't any specific changes they would make but "there are always improvements to be made and Black Barn pride ourselves on constantly improving and honing our events to create the best concert experience, safely, to those that attend regardless of its size".
A police spokesperson said police had a presence at the concert as is routine for similar major events and "noted that the majority of people were simply there to enjoy the show".
"There were a small number of people evicted from the venue for disorderly behaviour, and a small number of people arrested or warned for fighting.
The spokesperson said the total number of evictions, arrests and warnings was about five - one arrest for assault and one for disorder.
"Police always has discretion to either warn or formally charge people, it depends on a range of things including a person's history and the specific nature of the offending."
A Hawke's Bay District Health Board spokesperson said 16 people presented to the emergency department from the concert.
Two were admitted to the hospital and were in a stable condition.