WASHINGTON The BP oil rig explosion and spill wasn’t about anyone purposely trading money for safety, investigators on a special presidential commission said Monday.

Instead it was more about seemingly acceptable risks adding up to disaster. Investigators at the commission’s hearing outlined more than a dozen decisions that at the time seemed questionable but also explainable.

There was no evidence of a conscious decision on the BP rig to do things on the cheap at the expense of safety, investigators stressed several times.

Likewise, representatives of the companies involved in the disaster denied that corners were cut because of cost.

Critics — including a top academic, a congressman and people on the temporarily polluted bayou are balking at what they see as something close a free pass for BP’s history of cost cutting. Commission officials say they aren’t excusing BP at all, but pointing out there was no clear single decision that came down solely to money.

“Anytime you are talking about a million and a half dollars a day, money enters in. All I am saying is human beings did not sit there and sell safety down the river for dollars on the rig that night,” commission chief attorney Fred Bartlit Jr. said.

That doesn’t mean that a general culture of cost cutting wasn’t an issue, added commission co-chairman Bob Graham, the former Florida senator and governor. But Bartlit said that his job wasn’t to look at BP’s safety record.