Coach Brenton Sanderson was clearly angry at quarter-time after the side got off to a poor start and trailed by three goals at the first change.
Sanderson appeared to single out full-back Ben Rutten and fellow defender Daniel Talia in an animated quarter-time address.
Douglas said the coach had calmed down after the match, but questioned the players' mental strength.
"It was very disappointing, [Sanderson] gave us a good bake and we probably deserved it," Douglas said.
"We've got a lot of work to do, we've got to get mentally tougher, I think.
"We get in situations where we should win games, we play some good footy to get in those positions, but we seem to give up winning leads far too often.
"It's something we need to improve on throughout the summer and into next year."
Douglas echoed teammate Patrick Dangerfield's comments to AFL.com.au that the Crows have "played well in patches but just haven't been able to sustain it for a full four quarters."
Finals football is now mathematically impossible for the 13th-placed side; a fair assessment of where the Crows sit, according to Douglas.
However, the 26-year-old insisted the team would fight it out the season until the end.
"We've played some good footy, we've beaten Geelong a few weeks ago and we've pushed some good sides but we can't sustain that for four quarters," he said.
"Unless you can do that you're not going to be a top eight side or a top four side.
"It's disappointing you can't get [to finals] but ... we want to breed a culture where we're successful and we want to win each game we play."
The Crows will play Melbourne on Saturday in what will be their last game at AAMI Stadium.
Coincidentally, the longest-serving Adelaide coach Neil Craig will play a part in the game as coach of the Demons.
Douglas said it would be a "bittersweet" farewell to the ground he's called home for eight years and that having his ex-coach there would add to the theatre of the game.
"It'll be a bit sad I guess, I've been here eight years now and played a few finals out here and had some great memories,
"It's a great venue to play at especially when you've got a full house and you've got a lot of support ... at the same time it's exciting to move forward to the city.
"It's a bit strange that [Craig] will be there for the last game for the Crows at Footy Park, it's sort of worked out well I guess.
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