The Israeli international finished smartly from Dale Stephens's tee-up in the 51st minute to condemn the Magpies to a defeat at the Amex Stadium.
However, Hemed was caught on camera in the 88th minute appearing to bide his time before planting his foot onto Yedlin's calf, which could potentially land him a three-match ban.
The United States defender told The Chronicle after the game: "I was on the ground. Whether it was accidental or not, doesn't really matter, whoever is on the committee who punishes that sort of thing will figure it out.
"For me we have to learn from the day and move on. I thought he stamped on my calf but didn't see what happened. Maybe it was accidental.
"I was in the mix of things. Whatever it was it's not important. We are disappointed but take the positives from today and look at what we did wrong."
Newcastle sit ninth in the Premier League table following their defeat on the south coast.