White mx w/ multi colored specks - Interesting test result

[sixthseal.com]

This friend of mine tested a white mx (different batch from the usual white mx) with lots of multi colored specks (blue, red, brown, green are the dominant colors) with a Marquis reagent. It turned slowly purple/black.
However, the test with Simon's revealed a strangle bubbling reaction. When the Simon's reagent and buffer solution came into contact with the sample, it started to form many bubbles, and the liquid was very light orange.
This seems rather strange to me too, because he reported that the Marquis test did not bubble/smoke to indicate DXM. What could the results mean? Contaminated EZ Test kits? Or MDA? The Robadope test was not performed due to the large sample it requires, but I'll love to hear any input/speculation about what this could be before telling my friend to do the Robadope. Thanks everyone.

 

[sixthseal.com]

Just an update: my friend has done the Robadope and it didn't change color noticably. He did not skimp on the sample and the reagents are two months old and stored properly. He says that Robadope seems slightly blueish at first (almost undetectable) and after no further color change, he added another drop of Robadope, which slightly colored the solution to the Robadope color, but definately not near red/salmon. Any help would be appreciated. Thanks in advance!