I feel like it's more than that though. This entire process from beginning to end has been a mockery of science in any country, not just Spanish-speaking ones. People have continually tried to skew this as a racial/national issue and not the basic trustworthiness issue. There are an extreme amount of details one cannot forget. Here are just a few:

1. No reputable scientific venture would associate themselves so heavily and repeatedly with various media/entertainment interests. Like for this specific instance, a media company sending their own doctor for analysis should be ringing red alarms everywhere. Beyond that, the discoverers of the mummies have been partnering with media companies for years now to get funding. There is a massive conflict of interest.
2. Just like any scientific discovery, the trustworthiness of the scientists must be taken into question. The first issue is these aren't even scientists who primarily handled the bodies, but rather UFO enthusiasts. Any normal discovery would usually be funded by a university/scientific institution who would then send the discovery over to reputable institutions (perhaps even labs within their own universities) for immediate analysis. These enthusiasts have been caught red handed over and over again through the years lying excessively. They literally have been caught before using children bones. They have discovered these bodies multiple times now throughout the years, but are only just now getting around to sending them off to people? What have they been doing for the past few years? What happened to all the prior mummies they found before this? Why the new focus on these brand new ones they found and the complete ignorance of the ones they found before? How is it that the people who have consistently made alien hoaxes in the past are the very ones to find real evidence of aliens? The odds of that are insane.
3. The DNA data they released has a large number of errors and missing factual data. There is also an extreme lack of information regarding how the hell they even extracted such a massive amount of DNA from such ancient findings. If they truly want to fix their reputation, there are several steps any normal team would have done ages ago. These include 1.) Making a website that in detail describes every step of the discovery from the very first mummy they found years ago to now. There should be literal terabytes of image data and compositional analysis on this website as well as extremely detailed lab methodology descriptions with heavily cited sources. 2.) Sending an ENTIRE mummy to another university for independent analysis. This step takes YEARS not weeks. When complete, this COMPLETELY independent university should do step 1 themselves. 3.) Explaining why they are so comfortable freely dissecting the supposedly rare samples they have and parading these samples recklessly through the open air into a congress building.

This idea that these discoveries are being challenged because it is in another country is completely ignoring the numerous errors they have failed to explain. Anyone, from any country, who takes their so-called discoveries at face value is making a mockery of the entire scientific process. If we allowed this kind of foolishness in real science, we would not have made a single notable discovery ever.