Ian Sharps scored the only goal of the game three minutes before half-time at St James Park on Saturday when he glanced Ben Pringle's corner into the net, but the Millers were reduced to 10 men late in the game when substitute Mitchell Rose was sent off just two minutes after coming on.
"It is going to be a long trip home but the rollercoaster continues. We have got the good, the bad and we have not got the ugly yet," Evans said.
"The ugly is when you win when you don't play particularly well and we are having to play well to win the games. It is a big win. You have to respect Exeter as a team, they have beaten Bradford away and gone to the league leaders and thoroughly deserved their win.
"The only disappointment from my point of view is that we were not two or three at the interval. You always know you are going to have some pressure from Exeter. We said to the players before the game that we would settle for a thoroughly professional 1-0 victory. We had a disciplined shape.
"To come here without some of our key players and win is a good achievement. We knew we had players in the wide areas that could hurt them. I asked the boys to show desire and they did that in abundance."