2 of the soldiers that went with them were dissolved by antibodies......... so Clara could have been just as easily destroyed.
last but not least.... when the young female soldier asked to go with the Doctor in his TARDIS, she was turned down for being a soldier! What does he always turn his companions into??? The new Doctor, is he always going to be a hypocrite?
the writers need to bring it up a notch, this was derivative, and mentioning it reminds him of a movie is not a good enough excuse to go ahead with the plot.