In his first game in charge of the Reds, Gerhard Struber saw evidence of just why he got the call from the Reds hierarchy as his new side's defensive deficiencies and propensity to hand out gifts to rival sides was again showcased emphatically.
Three weak concessions took Barnsley's goals against tally to 36 - they only conceded 39 goals in the whole of last season at league level - and despite getting a fair bit right going forward, the Reds' soft underbelly was again exposed in a 3-2 Roses reverse.
It was frustrating for Struber, who stood on the touchline with his hands in his pockets quietly seething after the unmarked Bradley Dack settled the contest from time with his second goal of the game.
It undid plenty of good work from the Reds who had earlier levelled twice, with the second arriving eight minutes from time from Cauley Woodrow.
But sadly old habits die hard at the back, with Barnsley's charitable status being the story of their season.
It yielded a soft 25th-minute opener for Rovers with Dack netting after the hosts benefited from a poor pass from Mads Andersen - which was cancelled out early in the second half by substitute Conor Chaplin with Struber's decision to bring him on at the interval for the ineffective Patrick Schmidt bearing instant fruit.
Then, with Barnsley in the box seat and pushing forward for a second goal, Cauley Woodrow's loose pass was seized upon by Rovers, with the end result being a first goal in Blackburn colours for another substitute in Stuart Downing.
Thankfully, Woodrow atoned for that moment by netting a second leveller for the Reds with his seventh goal of the campaign from close in after fine work from Chaplin.
But there was one more twist.
Struber made his mark in his first team selection in making five changes, with chances given to his fellow Austrians Sami Radlinger and Schmidt, with Andersen, Ben Williams and Mike Bahre also recalled.
Going forward, Barnsley manufactured some handy enough positions, even if their final ball and option let them down at times, with Woodrow - in a deep role behind Jacob Brown and Schmidt - posing problems and seeing plenty of the ball.
But it was at the other end, for seemingly the umpteenth time this season, where the problems lied.
To give hosts, clearly lacking in confidence after one win in their previous eight matches, a leg-up was reprehensible with a gift-wrapped opener for Rovers representing the story of the season for the Reds.
Their obsession with playing out from the back at the wrong times and in the wrong areas has bordered on the reckless so far in 2019-20 and another damning moment saw Rovers make capital.
Loose play by Mads Andersen was seized upon by the alert Lewis Travis who sent ex-Reds loanee Adam Armstrong away on the right and with Barnsley stretched and exposed, he teed up Dack for an easier tap-in.
It was a gift that was gleefully grasped by Blackburn, who had offered next to nothing until that juncture in what was an extremely tame offering.
Prior to the opener, Barnsley went the closest with Woodrow, who had seen an early sighter held by Christian Walton, then denied by a far more expert block by the Rovers custodian after being set up nicely by Jacob Brown.
Well placed in front of goal, Woodrow, given his instincts so far this season, might have better.
It was still encouraging for the Reds, operating a 4-3-1-2 formation, with Aapo Halme going a decent job in front of the back four, with Kenny Dougall starting from the bench.
But familiar issues stubbornly persisted at the back, sadly.
To his credit, Struber was proactive in making two changes at the interval and the decision to bring on Chaplin yielded an instant reward.
A flowing move saw Brown surge forward and play in the forward, whose low finish was clinical.
It was the perfect tonic for the Reds, although they suffered a scare when ex-loanee Joe Rothwell seized upon a poor challenge from Radlinger, with his long-ranger effort blocked in the nick of time by the Reds keeper who had been stranded out of his goal.
At the other end, Barnsley were clearly fancying their chances, with the drive and energy of Chaplin offering the visitors a vibrant outlet.
Alex Mowatt then tested the reactions of Walton with an angled shot with Barnsley making a presentable case in their quest to take the lead.
That nearly arrived when a clever move ended in Mowatt seeing his curler flash inches wide as the hosts struggled for fluency at the other end.
But just when home supporters were starting to get irate, a lifeline arrived with another substitute making a key impact.
This time it was a home replacement in Downing, who fired home low past Radlinger after the ball broke to him invitingly after Toby Sibbick had blocked Rothwell's initial effort after Rovers raced upfield after Woodrow gave the ball away carelessly.
Woodrow redeemed himself by levelling, only for Dack to win it when he netted the rebound after Radlinger parried his initial header.
Blackburn Rovers: Walton; Bennett, Lenighan, Adarabioyo, Bell; Travis, Holtby (Downing 63); Gallagher (Graham 63), Dack, Rothwell (Buckley 79); Armstrong. Substitutes unused: Leutwiler, Johnson, Brereton, Evans.
Barnsley: Radlinger; Sibbick, Diaby, Andersen, B Williams; Halme (Dougall 45), Bahre (Thomas 83), Mowatt; Woodrow, Brown, Schmidt (Chaplin 45). Substitutes unused: Collins, McGeehan, Cavare, Thiam.
Referee: D Whitestone (Northants).
Attendance: 13,781 (1,315 Barnsley supporters).