Rum onload and document complete

What could explain the difference in RUM data loadevent vs document complete.

Document Complete Fully Loaded
Load Time First Byte Start Render Visually Complete Speed Index DOM Elements Result (error code) Time Requests Bytes In Time Requests Bytes In
6.294s 0.159s 0.693s 13.300s 5667 3499 99999 6.294s 104 200 KB 12.568s 291 2,907 KB

RUM First Paint domContentLoaded loadEvent
0.615s 0.816s - 0.816s (0.000s) 0.818s - 0.822s (0.004s)

Do you have a link to the test result? They should be the same but if there are several navigations it may trip something up.