equal opportunities?

I want to share a story that, although it didn’t affect me directly, is a sadly familiar story to me. I am in charge of a research group at a university in the United Kingdom. Two students from my lab got accepted to a very prestigious and selective conference in our field held in the United States. One of the students was Indian, the other one didn’t need a visa to enter the US. The Indian student applied for the visa plenty of time in advance, anticipating possible delay. Several months passed and they didn’t call her for the visa interview, and it became clear she won´t be able to make it to the conference. She notified the conference organizers, who then contacted me asking if I could attend the conference and present her findings on her behalf. Her work was worth going there and presenting it. However, I am originally from Asia, and I also need a visa to travel anywhere, and was not possible, given all the paperwork and application procedure, to get one on such a short notice. My British student attended the conference, presented her work and had the chance to connect with other colleagues. Having this conference presentation on her CV is a big boost for her career. The Indian student, who actually had more impressive research to present, did not get that chance. In no sense these two students have equal opportunities.