In snow and cold conditions, the home side were dominant in the set piece and with a strong driving maul that Hill conceded his team had failed to contain.
And with Exeter Chiefs next up at Sixways on Saturday he admitted his Warriors would have o work hard to get that part of their game right.
"On a day like today neither side were going to score tries from open play. It was too wet and the hands were so cold. Teams were going to score by kicking well and having a good scrum and driving maul," said Hill.
"I thought the half backs for London Irish kicked very accurately and put us under a lot of pressure, unfortunately our half backs didn't have the same accuracy.
"The driving maul was very efficient for them. We had worked hard at that, but today we came off second best. They were able to drive us at will and they scored two tries from a drive and the third from a scrum came after another.
"We had numerous opportunities five or ten metres out from their line, far more than they did, and failed to do the same.
"I am disappointed and we are all very disappointed because we have worked hard on our mauling strategy, but today when we needed it in wet conditions it didn't happen.
"We targeted this to try and break that away run, but the first 20 minutes we have conceded two tries to driving mauls," he added.
"On a day like today, when it was a big day for them, we fuelled the crowd and fuelled the Irish players. You've got to keep the crowd quiet and play well and start well - but it didn't happen.
"On wet days it is a battle of the forwards, if you win that and your half backs kick well it is not rocket science - you win the game. But we didn't have a strong enough platform and didn't kick well enough.
"We have got ourselves in a better frame of mind and work harder. The pitch at Sixways next week will be heavy, we've had rain and snow, and we have got to be ready for that sort of game."