Two players on the same base with contact

[Mi-Umpire]

OBR rules, no outs
Men on R1 and R2. After a over throw at first both base runners advance. R2 thinking he can make it home rounds 3B and R1 seeing this goes into 3B also. R2 rethinks and slides back to 3B hard. On his slide he inadvertently makes contact with R1 which is standing on 3B. There was another over throw at 3B so both runners go home to score. R1 never passed R2 at any time. So the short version is there were 2 offensive players on third base at the same time and there was slight contact between the two. Do both runs score, R1 scores and R2 out or R2 scores and R1 is out. Does it matter if 2 offensive players touch while on the same base?