foo.m

#import <Foundation/Foundation.h>

@interface Foo : NSObject
@property id what;
@end

@implementation Foo
- (BOOL)doingItWrong {
	return _what;
}
- (BOOL)doingItRight {
	return _what != nil;
}
@end

int main(int argc, char *argv[]) {
	Foo *hm = [Foo new];
	hm.what = (__bridge id)0xffff0000;
	NSLog(@"Whaat? %d", hm.doingItWrong);
	
	if(hm.what) {
		NSLog(@"This will print since we're not truncating to bool, we're interpreting the numerical value as non-zero, which is true.");
	}
	if(hm.doingItWrong) {
		NSLog(@"This will not print since we're truncating to bool.");
	}
	if(hm.doingItRight) {
		NSLog(@"This will print since we're putting the result of a comparison into the bool.");
	}
}

Could you run this on A7 device with 64-bit ARM? It should use correct _Bool type for BOOL and cast correctly.