Not sure if there is a way around this or not. That event originates from the bsnAPDisassociated trap which only send two variables:
bsnAPDisassociated NOTIFICATION-TYPE
OBJECTS {
bsnAPMacAddrTrapVariable,
bsnAPName
}
STATUS current
DESCRIPTION
"When Airespace AP disassociates from Airespace Switch, AP
disassociated notification will be sent with dot3 MAC address
of Airespace AP management system to remove Airespace AP from
this Airespace Switch"
::= { bsnTraps 8 }