Answer
Yes, Yakubu Gowon was part of the counter-coup in 1966. The counter-coup was carried out by northern military officers who overthrew the government of General Aguiyi Ironsi, a southern military officer. The counter-coup was motivated by the fact that Ironsi was a southerner and the coup had been carried out by northern officers. The counter-coup resulted in the death of Ironsi and many other southern officers.