ctor ate ▁Lev ies ▁at ▁D h ala ▁decided ▁to ▁am use ▁themselves ▁by ▁going ▁out ▁to ▁shoot ▁some ▁of ▁the ▁ham ad ry as ▁b ab o ons ▁( loc ally ▁referred ▁to ▁as ▁" rock ▁ap es "). ▁The ▁officers ▁drew ▁rif les ▁and ▁split ▁up ▁to ▁h unt ▁the ▁ap es . ▁In ▁the ▁semi - dark ness ▁one ▁of ▁the ▁officers ▁fired ▁at ▁a ▁moving ▁object ▁in ▁the ▁distance . ▁When ▁he ▁reached ▁the ▁target ▁he ▁discovered ▁he ▁had ▁shot ▁the ▁other ▁officer . ▁After ▁emer gency ▁treatment ▁Fl ight ▁Lieutenant ▁Per cy ▁Henry ▁Mason ▁surv ived ▁to ▁return ▁to ▁service ▁a ▁few ▁months ▁later . ▁When ▁asked ▁by ▁a ▁board ▁of ▁inqu iry ▁why ▁he ▁had ▁fired ▁at ▁his ▁friend ▁the ▁officer ▁replied ▁that ▁his ▁target ▁had ▁" look ed ▁just ▁like ▁a ▁rock ▁a pe " ▁in ▁the ▁half ▁light . ▁The ▁remark ▁soon ▁rever ber ated ▁around ▁the ▁R AF ▁and ▁it ▁was ▁not ▁long ▁before ▁the ▁term ▁was ▁in ▁general ▁use .[ 4 4 ] ▁ ▁Another ▁version ▁of ▁the ▁nick name ▁r ationale ▁was ▁that ▁the ▁German ▁Minister ▁of ▁Pro pag anda ▁Go ebb els ▁heard ▁the ▁legend ▁that , ▁if ▁the ▁bar b ary ▁ap es ▁on ▁the ▁Rock ▁of ▁Gib ral tar ▁ever ▁left , ▁the ▁British ▁Empire ▁would ▁cr umble . ▁At ▁that ▁stage ▁of ▁the ▁war , ▁when ▁things ▁were ▁not ▁going ▁well ▁for ▁the ▁A xis ▁forces , ▁he ▁decided ▁that ▁a ▁propag anda ▁coup ▁was ▁required ▁and ▁reported