It could be possible, but so unlikely that it would still be fair to say it is impossible. With a full or total metal jacket round, provided with a higher velocity load, complete penetration and ricochet is very possible. After this, though, the projectile would have lost much of its energy and (depending on the angle of ricochet)maybe some mass.
Now, when the projectile struck the other victim would have an ugly, mishapen hole with unpredictable penetration. The wound channel would be similar to a very low velocity pistol round in terms of terminality.
The whole would NOT be clean cut after the ricochet, also the round would have very little chance of causing death unless it struck a very vital area, the neck perhaps?
I don't know what circumstances this would have been in, but it is very, very unlikely.
