Husky Energy issued a release on Tuesday afternoon as a "clarification" of the timeline surrounding the leak of 200-250 cubic meters of oil into the North Saskatchewan River.

Earlier in the day, the provincial government released a report on the incident that Husky had filed with the Ministry of Economy.

That report said the company discovered a "pipeline release" or oil leak on the edge of the river last Wednesday night. That was about 14 hours before it notified the government and shut off the flow.

The incident report says that on July 20 at 8 p.m. CST "a pipeline release was discovered on the south shore of the North Saskatchewan River."

However, the company now says that report was incorrect; that Husky didn't know at that time that there had definitely been a "pipeline release."

In an email, Husky communications official Mel Duval confirmed with CBC that the report submitted to government was incorrect.

Husky now says "at approximately 8 p.m. the pipeline monitoring system indicated pressure anomalies as several segments of the pipeline system were being returned to service. This is common during startup operations."

'Did not identify a leak'

It said as a result of those anomalies the company analysed the data and sent a crew to have a look at the area but it "did not identify a leak." In addition, the company said that early Thursday morning it conducted an aerial surveillance of the area.

Early Tuesday, Al Pate, who's heading up Husky's response to the spill initially told media the pipeline wasn't shut off until Thursday morning around 10 a.m.

"The crews were on site shutting in the pipeline Thursday morning," said Pate. That's also when Husky notified the provincial government of the spill.

However Husky is updating that information as well. It now says "we decided as a further precaution to start safe shut down procedures at about 6 a.m."

When asked about the confusion and unanswered questions related to the timeline Pate said, "there will be a very full and comprehensive investigation that will deal with timing and those issues, but right now we're focused on the response."

When asked about the spill last Friday, Ministry of Environment spokesperson Wes Kotyk praised Husky for how cooperative it had been.

Wes Kotyk, executive director of the Ministry of Environment's Environmental Protection Branch, speaks to reporters in Saskatoon on Friday. (Chanss Lagaden/CBC News)

Kotyk told reporters the province had been notified as soon as the spill was detected.

"The company responsible, Husky Energy, has been very cooperative and as soon as they were aware of the incident they notified us," Kotyk said. "And they are working cooperatively to address any of the requirements that we've been having them do to address the situation."

The province said that Husky informed the ministry at the time they were able to confirm that a leak had occurred.

"The company is not obligated to inform the ministry of initial monitoring, or fluctuations in its line— only when it has actually confirmed the leak," a spokesperson for the ministry said in an email.

Pate told reporters he stands by the company's estimate that 200-250 cubic meters of oil were spilled.

"You know the key part here is we have very high confidence in the volume of spill. So we've got a sophisticated system that's commonly used throughout industry."

Company had an emergency response plan: Deputy minister

The deputy minister for the Ministry of Economy, which regulates pipelines, said Husky has an emergency response plan in place, filed with the government.

But Laurie Pushor doesn't know if it was followed.

"We want to do a complete and thorough review just so that we can understand what all their procedures and policies were, how their response related to that and of course what specifically happened in this instance," said Pushor.

He explained that most emergency response plans require the company to take immediate action.

"And proper notifications is a normal first step in those responses. So you want to deploy people to the scene and at the same time you want to be alerting all of the appropriate officials that should be alerted," Pushor said.

"Part of what a review needs to do is clarify exactly what was known when and how people responded and who was alerted when and so on,"

He said once that review is complete the government will be transparent about the results and he promised it will release Husky's emergency response plan.

Pushor said Husky inspected this pipeline as recently as 2015. He said the company has an ongoing spot-check regime, monitoring the surface and the pipe itself.

He also pointed out that the province does inspections of its own.

However he couldn't say how many inspectors the ministry employs and he didn't know when or if provincial officials had inspected this particular pipeline.