Hill admitted the tide turned in the second half with Worcester suffering two yellow cards.
However, the platform was built in the opening 40 minutes as Warriors stopped the famed Perpignan forwards building up any momentum.
"It was a very good performance and I thought the front five were very good. Euan certainly had the better of his opposition in the first half," said Hill
"That was the area we were concerned about, could they get their drive going, could they get their scrum going. But our front five were superb and the backs could give them all a pat on the back at half-time.
"It turned around in the second half, but I'm not sure we would have done anything different.
"I will look at the tape. We didn't change tactics or the team at half-time, but things started to go against us. But it is a hard game to referee in those conditions.
"We had five or six penalties at the start of the second half and that killed our momentum," he added.
"We were 16-8 up at half-time and just couldn't get going in the second half because we got penalised. We will look at that because I'm not entirely sure what happened.
"Neil Best flies over the top of a ruck and gets yellow carded and we lose another and are down to six men at a scrum. Eight of their big men against six of ours, we couldn't prevent the penalty try.
"At that stage it looked like the momentum was swinging with Perpignan, so credit the players to come back from that."