Been doing it that way for over 30 years. Course, that don't make it right.
I hate to admit to this, but the only time it was wrong was when we used aluminum or copper clad conductors, it weakens the conductor pretty badly.
I've had to administer/inspect/engineer some highly technical large scale projects and have done some fairly extensive research into this practice. I could find no definitive evidence that this was harmful, at least to copper conductors. If the guys are comfortable doing it this way, I see no reason to alter their practice, like we said, it's been done that way a very long time.
