A rib cartilage injury to star centre Kurtley Beale, which required a scan, was another concern for Gibson, though his side produced a barnstorming finish for a second straight week.
Beale left the field shortly before halftime and it's unclear whether he will be fit for next weekend's clash with Jaguares in Buenos Aires.
NSW led 7-0 after an early converted try to starting halfback Jake Gordon, but the visitors twice trailed by seven in the second half.
Both teams scored three tries in a scrappy mistake-marred match in which neither side ever led by more than seven points.
A 76th-minute try to replacement halfback and debutant Mitch Short from a devastating long range counter-attack, followed by a sideline conversion from five-eighth Bernard Foley earned NSW the draw.
Gibson acknowledged their scrum came under pressure in the second half but felt overall his tight five did an excellent job, and he was unhappy with the Tahs' overall performance.
"I thought we were pretty poor tonight to be frank,' Gibson said.
"At times we lacked ball control, we turned the ball over too much and put a lot of pressure on ourselves.
"I'm certainly not happy about our performance.
"We're not walking away rejoicing at all. We looked at our own performance and had a pretty honest assessment in the changing room and probably know that we need to get much better if we're going to be competitive in this competition."
NSW scored at the death to beat the Stormers in their opening game last week and again showed good fitness and resilience, following their sloppy execution through the match.
"What I am pleased about with the team is around the fight in our team, we don't give up," Gibson said..
"We're fit and we're giving our best so that's a good foundation to grow from."
The Sharks dominated territory and possession in the first half but were held to 10-10 at the break.
Springbok centre Lukhanyo An's second try pushed them ahead but impressive Tahs captain and openside flanker Michael Hooper then scored a long-distance try from a turnover.
Five-eight Robert Du Preeez raced over 40 metres to restore the home team's lead, but Short and Foley earned NSW a share of the spoils.
"We we were able to create a lot and then we seemed to stuff up,":Hooper said.
"We can be a lot better."