My suggestion would be to be direct with the tester: "The child was previously tested. We didn't feel the results were at all accurate and we are wondering about 2e issues.. Would you like to see the old test results and if so why or why not?"
Seeing the previous results may be informative in helping the tester choose the right test to use this time. Any good tester with experience with 2e gifted kids would be aware previous testing is a snapshot of a single day and may not be at all accurate for a variety of reasons. On some level if you really don't believe your tester is aware enough to make that distinction I don't think you have enough confidence in this person to invest in testing with her.
