Teams Sleeper Berth Rules

Here's the scenario: My husband and I are team drivers. I pulled into a truck stop on the 28th of June at about 1700, we couldn't deliver our load until 0900 on the 29th and I stopped about 100 miles from the consignee (last known truck stop). My husband started driving the next morning about 0630 and about an hour into his drive I got up to sit in the jump seat to read for awhile. A few minutes later we had to enter a weigh station in Mississippi. There were several DOT patrol cars in the station and we were waved into the parking area. When the officer came over to our truck he asked if I was a co-driver and my husband said yes. He then said that he needed to see my logs. I was still logged into the sleeper berth from when I had stopped the day before. The officer then told me that I was in violation because I wasn't in the sleeper berth. I explained that I just sat in the passenger seat to read. He said that I can't be in the passenger seat and logged into the sleeper berth that I have to put myself on line 4. I told him very politely "sir, I'm not working, I'm reading". He said that if I'm in the passenger seat I'm working and I should have put myself on line 4. He didn't write me a violation (nice of him, I guess). However he did continue with a level 1 on the truck, which we passed with no problem. The funny thing was he never even asked for my husbands logs and he was driving. Makes me think that the only reason we were pulled in was because he saw me in the passenger seat.

My questions are: How is sitting in the passenger seat with my feet propped up, reading actually working? Is he right about this? How am I supposed to draw a line and figure out where I made this change of duty status when the truck is rolling or bouncing as the case may be (which is why I left the sleeper berth to begin with)?

Maybe, I could understand if he had said I should be on line 1 and actually when I start my log to drive I usually show 8-10 hours in the sleeper and then go to line one for any additional hours that have incurred while my husband was "on-duty". However, I have never tried to update my log while the truck is rolling and didn't know that I was required to. I have tried to find anything in the regs that say sitting in the passenger seat is considered working. If this is true then I'm in violation all the time because I sit in the passenger seat when we are parked to read or use the laptop.

Hope someone can help clarify this for me. Thanks