Tk Throw is only 4 ticks, and Slow Time is only 1 attack. You're probably seeing either of them proc Combat Technique which throws up a second yellow number (but it can proc off of any attack so I've no idea why you're inflating Slow Time and TkT instead of all of them).
Ah yes, that's almost certainly it.
Which means that something simple like double-strike or project could even hit 3 times, for 15K damage to me. That explains a lot.