Luke/Starkiller
Mostly because he had zero interest in the man who was accepting of his lineage. Starkiller had considered Luke lesser for his teachings in the Force initially, as he did with Kenobi - though since his visions of his outcome and second betrayal Galen found himself considering many things in his life. This was one of them. Though the moment Luke had opened his mouth, Galen questioned his coming to talk to the Jedi.
"Hmph." Galen made a noise to the knowledge that Vader killed the Emperor. "Of course it was. There wasn't a loyal bone in that man's body." Galen though was ever obidient to his master, well till Vader indeed betrayed him a second time. Betray me once, shame on you - betray me twice, shame on me sort of deal.
"Interesting." Considering his next opinions. "I was trained by Vader."