Dennis Oland’s defence team went on the offensive Thursday, questioning some of the conclusions of the cellphone network expert.

Joseph Sadoun returned to the witness stand.

Sadoun is a cellphone network engineer and designer who analyzed cellphone tower coverage in the Saint John area.

He tried to determine where Richard Oland’s cellphone was, when it got a final text message on the evening of July 6.

The message connected to the cell tower in Rothesay.

Sadoun believes that means the missing phone was more likely in the Rothesay area.

Defence lawyer Alan Gold cast doubt on that assumption, and to do it, he used cellphone test calls made by Saint John police.

Police went to 15 locations, including the Renforth Wharf, not far from the Rothesay cell tower, but the calls made from there pinged elsewhere.

Gold asked, “So the test calls were one hundred per cent wrong, all of the calls went to an unpredicted cell tower?”

Sadoun responded, “Correct.”

In this case, the test calls bounced off a different tower well north of Saint John.

The trial earlier heard statements from two witnesses who say they saw Dennis Oland at the Renforth Wharf in Rothesay on the evening on July 6, 2011.

Those witnesses did not see Oland throwing anything away.

Oland told police he dropped by the wharf on his way home to see if his children were swimming there.

The final text came from Richard Oland’s mistress, Diana Sedlacek, who was in the Hampton area at the time.

Alan Gold suggested in court police should have taken a different approach:

“The best evidence is to go to the location of the send, and make some phone calls to see what cell tower they connect to.”

But under the Crown’s follow-up questioning, Sadoun told the jury the location of the phone sending the message, is not as important as the phone receiving the message.

With files from CTV Atlantic’s Mike Cameron.