Liljegren did not have a slow start. Slow compared to Sandin and Rosen, but much better than the rest of the season for him and better than most of the previous.
The AHL lists who was on the ice for goals. Liljegren was not on the ice for PP goals (after game 10 - plenty in the first 10 games). Sandin was on the ice for several PP goals and a SH goal against (again starting after game 10, same for Rosen - none before game 10, plenty after, and Subban was like Liljegren in this regard). If you want to make the argument that for the last 8 games before his injury Liljegren received a lot of PP time but the PP was so bad with him that they couldn't score, and that Sandin was not getting PP time but still managed to be on the ice to score 2 PP goals and be on the ice other PP goals/SH goals against, fill your boots. It just makes your argument way, way worse.
Second I went through Twitter posts at the time. Sandin and Rosen being moved to the PP was talked about at the exact time that the numbers support them being moved to the PP and Liljegren (as well as Subban) being moved off.
Continue countering your lies? Yes. I believe that lies should be countered.