However, Sanderson was full of praise for the manner in which his team-mates battled and performed before last gasp agony.
"It was a very high pressure environment out there and we certainly didn't feel like we deserved the result we got, a huge amount of effort went in," he said.
"For 78 minutes we were the better side in my opinion, it's a bitter pill to swallow, but I guess the only thing we will take out of that as a negative was the result.
"The way we went about the game, the manner we played the game and the energy and the physicality was great.
"We said before the start of the season, this is a bit of a watershed season for us and I think the players believe that."
Worcester's performance answered the critics who had written them off before the game but Sanderson insisted he did not care what people were writing about the club.
"I don't care what people think about us - I know what the players in the dressing room think and we know we are competitive," he added.
"We have come up against a side in Northampton Saints who are tipped for honours this season and we should have won.
"We will just keep quiet and get on with our job, everyone else is talking things over but we will get on with it in the West Midlands and get on with it next week.
"Hopefully next week we will produce the same sort of physicality, same sort of game plan and then we will be off and running down the road.
"It was a real battle, but I have never questioned the character of the guys. What we now need is a bit of a following wind so we convert these chances.
"We are bitterly disappointed with the result but the process was perfect, we need to reproduce that and we will get results.
"We believe in the strength and the quality of the players that we have got. We have shown against Saints that we can do it - it's just a question of consistency.
"The attitude of the guys, and the way they are feeling in the dressing room, I have no question that we will find that consistency."