"Also the fact that the SP didn't take off in anticipation of a buyout with 25 minutes left in trading, says lots too."

Yes, I believe it says they were putting the boots to this stock right to days end and the significance of the SRP would not be immediately apparent like 160m of 5%.

And now for complete speculation, wouldn't it be interesting to see the affect of a halt from a company that is known to have sworn them off. I don't believe that NOT does things to be timed with resource shows, however, combined with the clear and present danger of a takeover, if there was a time for needed theatrics, a Monday morning halt would do it. Posters tend to be on one side or another of NOT having news or a takeover in the works. Timing indicates it could well be both.