Some things don't count kills.

[ExecutiveOdin]

Drop a gas orbital on a group and watch them all melt but get no kill combo on your screen.
Same with land mines and the tesla tower.

Some stratagems just don't count toward your kills at all and you can see proof if you do an eradication mission.
We have done those with tons of land mines, killed 150 enemies, but kill count after match was a total of 30ish enemies.

Anyone know if this is a bug or intended?

[MJD24]

We've also noticed something similar. Some strategems do though.
Weird that it knows your minefield killed a friendly, but not that it killed ten Cyborg Commies