Wigan Athletic chief rues two dropped points
Latics were seconds away from securing a deserved victory at Spotland, until Stephen Humphrys headed home a 96th-minute equaliser to steal a point.
Despite Jim McNulty being red-carded for a two-footed lunge on Joseph, Dale levelled through Jake Beesley just before the hour mark.
Will Keane looked to have won it with a brilliant individual goal with 13 minutes to go, before Humphrys' late intervention.
And Richardson was left with mixed feelings after a game that for long periods provided so many positives.
"To concede in the way we did, after the way we played, I'm so disappointed for the lads for not getting the result they deserved in my opinion," he said.
"It's a funny game, football...Rochdale will feel they've achieved something, and we haven't...and yet the scoreline's the same for both sides.
"We had enough chances to have put the game to bed, not just the three-on-one opportunity, there were other chances, chances to get into better areas, and it seemed like only a matter of time before we scored again.
"But it's a learning curve for us, and when you do leave yourself open with a solitary goal lead, this can happen.
"We were still looking to push men forward, and it's up to us to kill the game off - and we didn't.
"Are we pleased with individual and collective performances across the board? Yes.
"I thought the lads stuck to their task, and I wouldn't be able to pick you a man of the match.
"Considering there were a couple making debuts, it was all a bit thrown together, the disruption to training with the weather, I thought the lads took on board the information brilliantly."
Nine of the 14 players on duty were graduates of the Latics Academy - another huge pat on the back for Gregor Rioch and his staff.
But Richardson says the disappointment of not coming away with all three points is a good barometer of how far the side has come in a short space of time.
"We're doing it tough at the minute, but when you've got senior players like Tendayi Darikwa, Dan Gardner, Tom James, Will Keane...these guys demand results and they demand the fine details are correct, as do I," he added.
"We're disappointed now, obviously, but once the dust settles, we can be so pleased with so many aspects of the performance.
"And if we can reach those levels most weeks, we'll be fine."
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