We can in fact verify the method. Server logs are incredibly detailed in that regard. It's text so it can't show "intent" on it's own, but it shows: the players involved, the weapon used, and the exact time it occurred.

So for example it might read something like this:

Player A Team Killed Player B at 5:03 with a P38 Luger.
Player A Team Killed Player B at 5:05 with a P38 Luger.
Player A Team Killed Player B at 5:06 with a P38 Luger.
Player A Team Killed Player B at 5:08 with a P38 Luger.

Player A Team Killed Player C at 5:09 with a G43.

Player A Team Killed Player C at 5:10 with a G43.

Combine that with a report/ping to an admin and you have a pretty unambiguous picture of what is going on.

Five kills in a very short span of time with small arms (which require the individual to ADS, Aim, and Fire each time) is HIGHLY suggestive of intent. The burden of proof you are looking for here which someone would require admins to be mind readers is just not realistic or plausible.

We do the best we can with the tools available to us. With regards to this specific instance I am very confident we got this one right. It's hard to know for sure sometimes, but it's not that hard to know with a very high degree of accuracy the vast majority of the time.

We don't let perfection become the enemy of the good.