They didn't say all recent graduates performed better than 50%, just the ones that they interviewed from Palestine. It sounds plausible that they only interviewed a handful and they were better than that 50%.
It was just merely stating a fact that Dalia and her acquaintance perform better in the hiring process than at least half the experienced engineers he has ever interview.
If anyone is jumping to conclusion its you guys
I don't know who "you guys" is.