Clarke's Saddlers looked to be heading out of the competition with five minutes of the second-half remaining as they had fallen a goal behind seventeen minutes into the first half as Omar Holness slotted the ball past on-loan Southampton stopper Jack Rose.
But, after the manager had opted to make a double change midway through the first-half, the Reds were able to regroup and went on to put themselves a goal ahead in three second-half minutes as Caolan Lavery (86') and a Alfie Bates-assisted Liam Connell own goal (89') looked to have booked their team a place in the Second Round.
However, Saddlers hearts were ultimately broken as Josef Wheatley was on hand to level the scores deep into second-half stoppage time giving the Saddlers another unwanted match and extending their run of winless games.
Speaking to the assembled media, Darrell said; "I have to take full responsibility. I started with the wrong shape, the wrong team and I was quick to rectify that decision.
"Making the changes early, being a goal down made it easier for me to make that decision. I saw that we weren’t working so changed to a 4-4-2 with a lot more attacking threat.
"The game was a lot more open and then we found some way to chuck away a game that we should win. It was a typical FA Cup tie, you have to give Darlington credit. I’m not going to stand here and say they didn’t deserve a replay, they’ve had a few chances themselves.
"We believe we’ve had a lot more golden chances and haven’t taken them. The lads at the minute are finding a way not to win football matches. There’s a bit of softness about it, mentality wise, which frustrates me.
"Sometimes individual players need to do some soul-searching and dig deep for themselves, otherwise their career will fall by the wayside. I’m hurting, struggling, but we’ll reboot again."