It's not unusual for folks that are not certified to perform checks on backgouging to assure it has reached sound metal.  We MT backgouging as a matter of routine on groove welds that will be RT'd or UT'd but no other NDE has been specified.  It's cheap insurance.  Normally it is performed by certified persons, however sometimes we allow uncertified but knowledgeable persons do that testing.

As long as uncertified testing is for information only, and is not used to replace testing that has been specified, there should be no problem.  But as you point out, training would be a good idea.  It helps a person to know thay performed testing correctly, to know what indications could mean, and to know how you can resolve questions about indications.  If nothing else, training would be a great confidence booster.

Yes eekpod I have been properly trained. Look at my post ... I never said I did not know what the indication was, or was not. I simply asked for an opinion. The reason for my question.....I suggested that the indication was LOP and needed more grinding; others had the opinion that it was a grinding mark. My question was put out to  see if any others would even consider it to be a grinding mark, and as I suspected no one did. You know one thing I have learned in this business is NEVER ask a question that you don't know the answer to, and always ask what others think.
  Having said that, all is good.......next up RT.