You could have some tension loss because of technique and the string meter should not be used to determine tensions and compared to the stringer tension but let me go a little farther. Could be wrong and if you think so please let me hear from you.
I don't think bad technique causes tension loss.
You can get different tensions using a bad technique but pulling some strings ffor more or less time than others. This will cause strings to relax at different rates and result in higher or lower tension on some strings. When you tension a string and remove the tensioner you will more than likely see some drawback. But by clamping the strings as close to the frame and tension as possible most of the drawback is on the next pull. But here's the kicker - if the string slips in the clamp you have some big problems one of which is recovering drawback. But that is not technique that is setup. You will have more issues from improper setup and maintenance problems like dirty clamps than anything else.
I would like to apologize to anyone I have not offended. Please be patient I will get to you shortly.