Town looked comfortable following Jason Scotland's 58th-minute opener and were good value for their lead until Simpson's late intervention.
Jewell said: "We looked a bit tired in the last 15 minutes. I thought we deserved to win on the balance of play but there's only one stat that counts and that's the goals.
"But at least we're making progress and that's the most important thing. It was as well as we've played since I've been here.
"Doncaster had 406 passes on Tuesday night and we had 280, yet won 6-0. That shows you that domination and possession is great, but it's what you do with it that counts.
"I thought we were terrific and the only thing lacking was goals. Some of the football we played in the first half especially was scintillating."
Source: PA
Source: PA