Runner does not touch plate, enters dugout

[Bluefoot]

Men's SP ASA. R1 on 1B, no outs. B2 hits long base hit to deep right field. R1 rounds third as ball is relayed from the outfield. F2 sets up facing right field with his left foot blocking edge of the edge of home plate that faces 3B. Relay throw to F2 is towards first base dugout, so F2 has to stretch to his right to make the catch, but does not move his left foot from its position on the edge of home plate. Then R1 steps on F2's left foot without touching home plate. F2 spins/sweeps around to try and tag R1, but R1 has already passed by and continues into offensive team dugout area (past fence) on first base side. I make no call until R1 has entered dugout area. F2 states "I blocked the plate!" I believe that I can't call obstruction on F2 since he had possession of the ball before R1 stepped on his foot blocking home plate. I can't call R1 safe, since he never touched home plate. I can't call R1 out on the tag, since F2 never tagged him. Once R1 passes the fence I call R1 out for entering the dugout area. Of course, offensive team is not happy with the call.

Is my reasoning in making this call correct?