Loew's emotional outbursts are a rare sight but he had good reason to feel aggrieved.
The Germans, without an international title since 1996, have great expectations when they travel to Brazil in June, hoping to lift the trophy for the fourth time and become the first European team to do so in a World Cup on South American soil.
However, their display in Stuttgart was far from convincing.
"We have to really improve in the coming months," Loew told reporters. "We just could not show any dominance and saw how tough Chile are. There is still a lot of work to be done.
"It is always very good to see that it is not just Germany that has good footballers," added the coach, who two days earlier had challenged his players to prove they were ready to secure a place in his squad.
Their trademark quick passing game was neutralised by a hard-working Chilean team that qualified for the finals as the third-placed South American team.
The Germans offered little to counter the pressure, sending inaccurate passes all over the pitch while their defence continued to look like a work in progress and a possible Achilles heel at the tournament.
Central defenders Per Mertesacker and Jerome Boateng had trouble adjusting to the pacy Chileans and were repeatedly caught out of position.
Germany could have walked off as losers had it not been for half a dozen missed chances from a less-than-clinical Chilean attack.
With captain Philipp Lahm shifting from his fullback berth into a midfield role, Loew moved Kevin Grosskreutz to the right of defence and put Marcell Jansen on the left.
Jansen managed just 24 minutes before limping off with a ligament injury while Grosskreutz struggled to contain the South Americans from the wings.
It was only thanks to a brief glimpse of their passing game, with Mesut Ozil setting up Mario Goetze, that Germany went into the break with a one-goal lead.
The Germans are drawn in a group containing Ghana, the United States and Portugal and their game against Chile was designed to give them a feel for the South American teams they could potentially face in the knockout stages of the tournament.
"It was a good lesson for us and it was good for our mentality," Mertesacker said. "The Chileans showed us how to play good and productive football."
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