If you listern out for long enough you will find every one makes mistakes.
There is some very poor RT around from even the best pilots and controllers.
If your losing sleep about doing your RT oral exam (like I was) book a few hours ground school with your examiner before your test. he/she will set you straight, i did a day at gamston with "True" had blast and learnt loads! then did the exam worth every penny.
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read back all instructions and anything with numbers in
works for me