Hadden's Scotland were leading by ten points at halftime in last weekend's clash with the world champions, but let that lead slip in the second period.
They ran in 14-10 losers, much to the displeasure of the coach who said,"The game was there for the taking."
Had Ruan Pienaar not slotted four penalties after half-time and Jaque Fourie not dived over in the left corner, things may have been very different, and memories of the 21-6 victory at Murrayfield of 2002 rekindled.
There are however some positives for Lions' bosses to take from the game. With Hadden's scrum half, Mike Blair being a leading contender for a place on the Lions trip next summer, the Murrayfield experience will stand him in good stead in future encounters with the Boks.
But, the defeat was painful for a Scotland side who held the victory cards in their hand. Hadden summed up the feeling of the dressing room saying, "It's difficult to explain how gutted we are."
His opposite number, Peter de Villiers has watched his side stutter over the finishing line in the recent matches with Wales (20-15) and the four-point win over Scotland, hardly ideal preparation for the visit of the combined Isles side in the summer.
And with six warm-up matches before the first Test in Burban on June 20, the tourists will have had the chance to build the momentum necessary to beat the world champions in their own backyard.
Next up for South Africa is Martin Jonhson's England at Twickenham on Saturday.