My team for whatever reason concedes less goals when I use an attacking mentality; can anyone explain why?

Oddly, my defenders have lately made a habit of scoring on the counter-attack when I'm using attacking, whole pitch pressing w/o counters. Today's cup match it was 2 of my 3 goals scored by defenders on the counter; one had red arrow, the other had no arrow. Last cup match, by blue arrow DC, scored on the counter, when I was using attacking, down the flanks, whole pitch, w/o counters. Is their any explanation for this? Or just a bizarre random occurance?