If the shooter is lefty, he has no chance of pocketing the five and drawing back. He'll be bridging off the rail which will inevitably elevate his cue which will cause the cue-ball to jump a little. Any bit of a jump and that cue-ball will no longer be hugging the rail.
With that said, you simply cannot hit this ball hard. Even for a right-handed player, there is a huge risk. I mean, I'm sure it can be done. It's not absolutely impossible to make this shot firmly but you'll miss it more often than not this way.
If you want to get out, you play the shot softly and take the difficult cut on the 6. The nice thing about the long cut-shot is that the position on the 7 should be automatic. This isn't an easy rack. Even with ball-in-hand on the 5, it's challenging since you're constantly going up and down table. To win, you have to evaluate each shot responsibly and opt for safeties when appropriate.