I'm sure Peter Roberts is a fine professional, however, I have passed border patrol/immigration personally this way dozens of times and know of many other people who do it. You can find people doing this in an instant if you want.
I once got in trouble with BP because they didn't believe me that I was coming in to work on a project and thought I would be looking for a job to stay illegally. BP finally decided to let me in and told me that what I was doing was fine, but they just didn't find it credible that I would leave my GF alone for a month in Argentina.
I commented as a "not lawyer" since it wasn't clear if the lawyer would answer and I have extensive experience, research, and have discussed this with lawyers. Just trying to be helpful.