Did my Tau opponent cheat?

[jackedup]

Last game my Tau opponent fired some markerlights at my guy on overwatch, and then used the counters to up the BS of other troops firing on overwatch. Some people tell me he can't do that and cheated. 

Anyone with a Tau codex can help to clear it up please?

[vgnevar]

Tau can use Marker-Lights fired during Supporting Fire to up the BS of other Supporting Fire or Overwatch units during that assault.

He had to snap fire the Marker-lights as if shooting them in overwatch as well.

That my friend, is completely Tau Codex legal.

[baconslice]

Yep it's legal. It does say somewhere in the dex. You just can't carry them over to subsequent turns or phases.

[innocent]

Cause otherwise it would be just OP... /sarcasm