Malcolm, 2nd Thane died in 1217. Alwin's birth shows circa 1240, which isn't possible. The non MP profile for Alwyn de Callendar, Thane of Callendar[1, Thane of Callendar linked to Malcolm shows the birth "before circa 1217".
Not adjusting death year would then make for an exceedingly old Alwin. Perhaps the dates for this profile are for a different Alwin de Callendar.