Millwall boss Kenny Jackett was unhappy with Bolton's opening goal as they eventually fell to a 2-0 defeat in the FA Cup fifth round at home.
Japanese starlet Ryo Miyaichi latched onto a quick free-kick from Sam Ricketts in the fourth minute and held off the challenge of Alan Dunne before finishing with ease.
And Jackett questioned the awarding of the free-kick, saying: "Whether it was a free-kick or not is debatable but they took it quick and to give a Premier League side a start like that is disappointing and gave them something to hold onto - basically after that their game plan was to sit deep."
However, Jackett admitted his side's lack of a cutting edge cost them in the end as David Ngog doubled Bolton's lead just before the hour mark with a strike from 25 yards.
"We had a lot of good possession and some good moves without being able to get that goal. There were some key moments - their full-back (Gretar Steinsson) nearly scoring an own goal in the first half and then a good double save by the goalkeeper," he said.
"We need one of those moments to break for us because that would have obviously got us back into the game."
Jackett wants his team to learn from the game but insisted his players can be proud of their efforts.
"They have got a good ball retention about them and the first pass is always very safe and it is something we have to learn from," he said.
"It was a good run in the FA Cup and we haven't disgraced ourselves today but we have to look forward very quickly now."