Resnet-50 finetune BN layer use_global_stats

[johnson-magic]

hello,everyone,I am using Resnet-50 to finetune my data.I have a question about BN layer param "use_global_stats".

first,i learn that this param should be false when traing; when test should be true。
Now in train_val.prototxt i set this param false,and add Accuracy layer to see the train accuracy and test accuracy 。
i find "test accuracy" output by train_val.prototxt is very lower .And when i use"caffe/build/tools/caffe test -model test.prototxt -weights xxx.caffemodel",the "test accuracy" is higher.
I think this is because the first "test accuracy" is computed by train_val.prototxt whose use_global_stats is set to false. which "test accuracy" is beleviable ? anyone have this question too?why official train_val.protxt don't need accuracy layer ?
thank you