The two-time Olympian looked calm and confident as her music started, but pulled out of her opening triple lutz - only rotating twice to execute a double jump.
"I was in shock, I don't know what happened. I'm still trying to process it," Kailani said.
"That's so uncharacteristic of me and it shook me a bit. It felt like I picked too heavy on the takeoff and didn't run my edge."
But in a remarkable show of courage the 23-year-old rallied quickly, completing a triple-triple combination and a double axel.
"I was really proud of myself for getting straight back into the program and feeling really present in the music, it felt really emotional and I gave it my best.
"The hardest part is knowing that I can do so much better than that, and I'm sorry if I disappointed anyone.
"I felt like I had the most support I've ever had from people back home and it hurts that I couldn't deliver for everyone."
Her short program score of 49.93 was not high enough to proceed to the free skate on Thursday.
Despite an early end to her Beijing schedule, it's not the end of the road for the talented figure skater - who will return to competition for the World Championships in March.
"I'm determined to come back stronger from this. Right now it hurts, but once I have time to process it I'm going to learn from my mistakes and be better."