Supposedly Melani also knew in the days previous that he wasn't feeling well. Why would Alex call Lori, in HI, before his own wife--someone who could actually get him medical assistance? Or, even, 911? Was it to say to her, "What.... Have..... You..... Done...?!?"
ETA: just reviewed dateline. There is no indication Lori and Alex had a phonecall wherein his death was imminent. It's left open that possibly Lori was using her magical Spidey-sense which told her Alex was not ok. I assume if that's the case she has been bitten by a radioactive Black Widow.
MOO