Last Out

[Fearnone]

Had a tough call today for the last out. Here is the situation... 2 outs on the visiting team with R1 on first, throw back to first base from catcher. R1 dives back as the ball arrives, she touches the base and as the first baseman catches the ball, she falls on R1's arm. R1 pulls arm off the base and is tagged by baseman. I was BU and called R1 out. After the call R1 is lying on the ground in pain, coach says she was injured and should be safe. PU saw the injury occur but after conference we decided that no time was called. Correct ruling? Final score 4-3, home team