BP ignored the concerns of its contractor over the cementing of the Deepwater Horizon well shortly before it ruptured, a US hearing was told.
Halliburton official Jesse Gagliano told US federal investigators in Houston, Texas, that he was at odds with the oil giant over the need for additional centralisers - devices used to help plug a well.
But BP's lawyers pointed to emails written on the morning of the blow-out to Mr Gagliano that suggested that the contractor was happy with the procedure.
"We have completed the job and it went well," a rig engineer wrote just hours before the rig exploded, the hearing was told.
Meeting yesterday, the investigating panel in Houston heard that BP rejected recommendations from Halliburton to use 21 centralisers during the cementing job.
It feared that without them there could be an increased risk that the casing would be off-centre - a problem that may have led to the explosion.
Instead, the oil giant opted for six centralisers. BP's well team leader John Guide objected to the additional devices due in part to the additional time it would take to install, it is claimed. "I do not like this," he wrote to a colleague prior to the explosion in reference to the additional centralisers.
The April 20 blow-out in the Gulf of Mexico resulted in the deaths of 11 workers and the worst environmental disaster the region has ever seen.
Since the accident, BP has come under attack for prioritising speed and cost-cutting above safety.
Outgoing chief executive Tony Hayward was accused of presiding over "astonishing" corporate complacency during a Congressional hearing in Washington earlier this summer.
At today's hearing, Mr Gagliano accused BP of ignoring concerns over insufficient centralisers in a bid to speed up the process.
"BP then in turn decided not to run the additional centralisers without consulting me or their in-house specialists," he told the panel consisting of Coast Guard and other agency officials.
But the firm's lawyers said that an email to Mr Gagliano from Halliburton's on rig engineers written three hours before the blow-out failed to mention these concerns.
During yesterday's hearing, an employee for Transocean, the contractor operating the rig, said that a pressure test problem was resolved shortly before the explosion.
Daun Winslow said he was given the "thumbs up" by Transocean's highest-ranking member on the rig.