That's no big deal. When you transfer via lightpipe, if a data error occurs, it goes undetected. I doubt that they are common, but if one does occur, there's no way to correct it. Probably not worth worrying about.
Transferring via lightpipe in real time is a perfectly reasonable way to do it, and it wasn't my intention to imply otherwise. And if you're doing a rough mix for a client, that's a pretty good reason to take that route. In my situation, if I need a rough mix, I need it at the time the recording is made. So I have to make it live. By the time I get my raw tracks home, the musicians are already on to another city.
If you have headphones that really block the outside sound (by 24 to 30 db), then you can do some monitoring even in noisy environments. There are a number of companies that make headphones with that degree of isolation. But I'm sure your approach works fine for you. I like to hear what I'm recording. Again, no big deal - just different ways of working.