It's 100% seniority in most universities, and mine is no different. I'm a few years below, so my word is trash compared to butterhuffer's. He isn't "impacting" anything, since his lab is already doing a "favor" for even letting us use their shit. I've already tried to talk to his PI, and the enabling butterhuffer says I need to work by his schedule or fuck off. PhD isn't the same as normal "studies". What works as an undergrad doesn't work as well in graduate school.