Alex Kountouris, Cricket Australia's manager of sports medicine, told a news conference in Australia on Monday he was "100%" satisfied with team doctor Richard Saw's treatment of Smith in London on the weekend, and he urged against any over-reaction to the sport's new concussion guidelines.
Smith had to leave the field after being hit on the neck near the rear base of his batting helmet by a fast, sharply rising delivery from Jofra Archer on Saturday. Saw conducted tests before allowing Smith to return at the fall of the subsequent wicket, and the ex-test captain was eventually dismissed for 92.
Smith complained of headaches later Saturday and was ruled out of the remainder of the match on Sunday after displaying concussion symptoms.
Marnus Labuschagne replaced Smith, becoming the first concussion substitute in international cricket, and scored 59 in an important innings that helped Australia draw the match at Lord's and retain a 1-0 series lead in the five-match series.
"The reality is only about one in five or six head impacts end up in concussion," said Kountouris, who added that Cricket Australia's research showed delayed concussion accounted for up to 30 percent of those cases. "If we pulled out every player who had a head impact, we'd be pulling out 80 per cent of players who don't have a concussion and taking them out of the game. So that would be an overreaction."
Kountouris said three other batters were hit in the head, but only Smith had a concussion.
"He didn't have a concussion at the time (Saturday)," he said. "If we took him out of the game, we would have been leaving him out of the game for no reason other than what we saw on the field.
"Our doctor is an expert in his field. He's trained to pick up even the minor signs of concussion. Everything he did was according to the protocol, he was very thorough and ... we're 100% happy with what happened over there."
The third test starts Thursday in Leeds, making Smith a doubtful starter.