I was there, though I didn't personally see the hit. However, there are interesting notes with supporting evidence from the screenshot:
* Round had just started -- all that "suicide spam" is from the teams switching around (that happens at the start of the round not the end of a round so this was not an "after-victory team kill", this was a round-start team kill.)
* Truehero killed him and then immediately logged off
Sometimes people TK at the start because they are stupid and it was an accident. Killing someone and logging out is usually someone doing it on purpose and thinking they can dodge the consequences by logging off before any admins can deal with them. That really rustles my jimmies.