is one piece episode 146 filler?

In a bar, Roshio and Bellamy are gambling and Roshio wins. However, Bellamy refuses to accept defeat and insists that Roshio cheated by having Sarquiss bear false witness.

Roshio tries to fight Bellamy but he is defeated easily. The Straw Hats were still at sea and trying to locate Jaya when Chopper commented about the Seagulls flying above; then suddenly the Seagulls fall and Chopper states they were shot.

Usopp comments that only an extraordinary marksman would be able to have shot them and it is more likely that the shots were random.