Quick question after a heart breaking loss

[WayzataXC05]

Hi

I'm a senior in high school and just had my last game of my career. We were playing for the consolation game. We were down big and came back to with in 2 with 4 secs togo. I got and fouled and made both free throws (best game of my 10 year career!) to force it into ot. We had a lead but blew it. With 20 secs to go we were down by 3 points. My friend (best shooter on the team) put up a three and got fouled. He missed the first and made the second. On the last, being down by 2, he intentionally missed it. It went off the backboard, hit the front end of the rim and we got the rebound. The ref called it dead because it was an "intentional miss by the free throw shooter." The other team got the ball and we ended up loosing by 4. After the game we asked the ref about the call. We had never heard of the rule, and even if there were such a rule it looked like it was a decent shot that almost went in.

SO my question. Is there any such rule about intentionally missing free throws? I'm not sure which rules we play under, but i think it's minnesota state high school rules.

Thank you