Paul di Resta thinks Force India got complacent in Q1 in Monaco and threw away a chance to qualify in the top six.
The Scot was eliminated in Q1 and will start 17th, a result he described as "probably the most painful experience I've ever had in qualifying".
Earlier in the session di Resta had been a frontrunner, and he believes that made the team feel too secure, leading to an errant call to stay out on worn intermediates as others changed to fresh tyres.
"Probably what threw us was that our performance on inters at the beginning was very successful," said di Resta when asked by AUTOSPORT how the session had gone awry.
"We were well within the top three, better than we imagined, and maybe we felt a bit too comfortable.
"If we'd been in a bit more trouble and put a fresh set on, we'd have been easily through.
"In sector one and two, I had no rear tyres to get through the dry sector three.
"If it stayed wet, which I hoped it would have - because the performance in the beginning was a big step over where we have been in the wet - I think we would have been easily in Q3.
"And in the dry, we were P7 this morning but with quite a bit more potential still to go."
He believes Force India should make changes to ensure the Monaco situation does not arise again.
"There are procedures that probably need to be improved in how we make decisions," said di Resta.