"It broke my heart," Ambridge said in an interview with Stephen Quinn on CBC Radio One's On the Coast.
It was last month when Ambridge’s seven-year-old son Miles came home from his New Westminster, B.C., school with the picture in his backpack.
But when Ambridge took a look, he says he was disgusted by what he saw: 22 Grade 2 students lined up neatly in three rows, their teacher standing to the left with her students, and to the far right, Miles in his wheelchair.
"He’s leaning in, he wants to be included," Ambridge said.
"It’s a mix of humiliation for your little guy and sadness and you know, a little bit of anger. The problem is where do you put that anger?"
Miles has spinal muscular atrophy, a genetic disease that attacks the nerve cells — called motor neurons — in his spinal cord.
Ambridge said he put the photo away and chose not to share it with his son. Instead, he penned an angry note to the class teacher.
"It basically said, 'I find this photo disgusting. Please throw it out. I don’t want it in my house.' Painful, very painful. It still hurts to see it."
Ambridge said he thought the photo was dismissive and harmful, but stopped short of calling it discriminatory.
"For me, discrimination is a wilful exclusion of somebody. I don’t believe that’s a case here in any way, shape or form," he said.
"I think what it is, is just a circumstantial lack of awareness that resulted in a really emotionally tragic output."
Ambridge said the school responded immediately, first with a personal call from the principal and then, a plan to reshoot the class photo.
Ambridge said the original photo does not reflect how Miles is treated at school day-to-day.
"He’s been wonderfully accommodated. The kids love him, he loves his peers. The staff have always been terrific with him," he said.
But he thinks the school and everyone involved can work harder to make sure Miles is included.
"Be sensitive to our differences, but don’t highlight those differences, accommodate them," he said.
"I hold myself to account for making mistakes in [Miles'] daily life as well. I’m a parent. You do your best on a daily basis, but I’m not above it either."
In the original class photo, Miles is beaming, seemingly oblivious. But it's that innocence that caused Ambridge to feel even more protective of his son.
"He doesn’t carry that perception of any wrongdoing or malice. He’s just trying to be part of the picture and he’s having a great time doing it," he said.
"I think that’s part of the pain for me … it's just so innocent where you start thinking 'How dare you?'"