It matters for the validity of the experiment, yes. Bear in mind, the chances of the experiment being real were astronomically small, as university professors a

It matters for the validity of the experiment, yes. Bear in mind, the chances of the experiment being real were astronomically small, as university professors are not normally in the business of torturing members of the public. As there were (iirc) small rewards given for taking part, the rational thing to do is follow the instructions. This seems like an inherent problem for attempting to study order-following in a lab.