X-Raid BMW team boss Sven Quandt says the Dakar Rally organisers should have foreseen the problems with yesterday's Fiambala to La Rioja stage.
Even the front-runners struggled to get through the stage without getting stuck or having navigation issues, and rally leaders Giniel de Villiers and Mark Miller were both highly critical - with Miller questioning whether any of the amateur crews would even reach the finish.
Quandt, whose team led the rally with Nassar Al-Attiyah early on, said the Dakar organisers had misjudged the likely conditions.
"I think the biggest thing is that they should know that in summer time it's different to in winter time," he told autosport.com.
"And secondly, after three hard stages, they could have prevented today in my opinion - knowing that after three days where they already had problems, that this was going to be a problem.
"I'm a bit astonished, because the organisation should know a little bit better. They've done a very nice race, but at the moment there are still 90 cars and trucks (stuck) before 170 kilometres into the stage, and that's a bit too much.
"I know there was not a lot of time from last year to this year to prepare this, but there are plenty of local people who know that in summer time it's different to winter. When I was driving here in February, my experience was that when it gets hot, the dunes are very hard to climb, they get extremely soft.
"In Africa, the time of day when you climb the dunes is not such a big difference as it is here. In the morning you can go almost like it's asphalt. In the afternoon it's soft like you cannot believe. The variation between morning and afternoon is extreme.
"I think it's unfair to a lot of competitors who will get penalties today."
De Villiers had slammed the official road book's instruction for stage 12, describing it as "pathetic", but although Quandt agreed it had been inadequate yesterday, he felt it was generally sufficient.
"For me whoever did the road book is absolutely okay, except today we had some criticism that in the middle (the drivers) said they took their own route and didn't follow the road book because it was stupid," he said.
"Their results show it was the right decision to get to the waypoints and then look for your own route in the dunes. I think you should take a local guy when you do the road book, who can tell you what is possible and what is not possible in summer time."
Quandt added that he had always expected the Dakar's new location to provide a huge challenge.
"A lot of people said it would be an easy rally this year, but before Christmas in all my interviews I said this would be one of the most difficult Dakars that you have seen," he said.
"When you've been here, you know that it is difficult because it varies between sand and gravel a lot, and you have got hard and easy parts mixing up all day. Here you are driving on hard terrain and you feel nice and comfortable, and then you have to change your driving style and that makes it difficult.
"I think they've learned a lot this year, and for sure they will change. I hope they will not go the opposite way and make it too soft. They have to find the right balance - have one or two hard days, but find a way that everyone can finish."