I experienced something like that a day or two ago. I can't remember the guy's name (he was a low-ranking noob), but he was bombing my carrier and was completely invisible on radar and visually. I waited at the red base for him to reload, and at his carrier to reload and never saw him. I just got disgusted and left.
Tonight me, Manic, and ". ! m" were playing a round in the South Asia server, and "Enoxx" from the DN squad was completely invisible when he was bombing. We questioned him about it, and he said he had found a "trick" that made him completely invisible both on radar and visually, and worked for him in 90% of the servers he entered. How can this be stopped??????? It's going to completely ruin gameplay if left unchecked.