Jeremy was obviously not expecting the seriousness of it all,,as something other than " one of Sheilas' turns " wouldn't have entered his head,,nor would he have known how a situation such as happened,,was handled.
The very fact that he felt he needed to let someone know,i.e.JM, tells me that he was never used to urgent,or unknown situations.
If it had been in the daytime,,Jeremy himself would have driven along at break-neck speed probably,,but getting a call at that unearthly hour would have startled him,,particularly if he'd been in a deep sleep.