NEW ORLEANS (AP) — An executive from the company that was BP’s cement contractor on the Deepwater Horizon drilling rig testified Monday that he learned of some “irregularities” in tests that the contractor’s employees performed after the massive 2010 oil spill in the Gulf of Mexico.

Timothy Probert, a Halliburton president who served as the company’s chief safety officer at the time of the spill, didn’t specify the nature of those irregularities during his testimony at a trial designed to assign fault to the companies involved in the deadly disaster.