Terribus- After 1998 BP had seven years in which to carry out upgrading on the refinery. They paid in lives and a felony fine.
Other short-comings after 2005 were not corrected by 2009 when another fine was levied.
Personnel hired originally by Amoco probably continued working after the BP takeover, but they were now supervised by BP and procedures were BP revised and approved.

Although job loss would have been significant, perhaps the government regulatory body should have required closure of the plant until corrections were made.