He and New Zealand Principals' Federation president Cherie Taylor-Patel say student violence has risen as New Zealand grappled with Covid 19.
Taylor-Patel said she hoped the student would recover and did not suffer any ongoing trauma or damage.
"Every student has a right to be safe, and everyone has a part to play in that."
Taylor-Patel said there had been a rise in the number of assaults, like this one, being filmed and posted on social media during Covid.
"We have seen a rise in aggressive, vexatious incidents caused by anxiety, stress, mistrust.
"These incidents are becoming more common, but we need to push back and ask why is this happening, what's causing the aggression?
''There's a cone of silence around the incident as it is investigated.''
Taylor-Patel said teaching young people self-management skills to manage conflict without resorting to violence was also the responsibility of whanau.
"Students also need to be educated around appropriate use of social media where incidents like these are not normalised.
"Right now there's an overlay of tension, stress, pressure, playing out in all sorts of ways."
Lyons hoped schools would alert non-profit online safety organisations like Netsafe about such videos.
He said they were potentially harmful for those being filmed and viewers.
"Since the lockdown we have certainly seen an increase in harmful content online, and more and more videos involving young people.
"Some people record them to be helpful bystanders, so it can be used as evidence. In those cases it's laudable.
"But, in some cases, videos are used to try and shame or threaten or harm."
He said young people were motivated to film or share video by a desire to share "exciting stuff", and to let peers know they were at events.
A St John spokeswoman told Hawke's Bay Today a student had been taken to Hawke's Bay Hospital in a moderate condition.