Here's what I found and I think you're right. The original quote:

DAVID HOGG: On the day of the shooting, I got my camera and got on my bike and rode as fast as I could three miles from my house to the school to get as much video and to get as many interviews as I could because I knew that this could not be another mass shooting.

Seems pretty damning, but I think he's referring to later in the evening:

In an interview with Vox that was published Feb. 20, Hogg said he rode his bike back to the school at 6 p.m. that night with his camera to do more filming. He was interviewed that night by Fox News.