Does this seem like an abuse of police power?

I had a strange traffic stop incident Friday Night. I live in River Vale, New Jersey, about 2 miles south of the NY/NJ line. On Friday night, I was at a bar in Rockland County, NJ with a few friends. I had 2 beers over a period of 3 hours. I left the bar a bit after 9 and headed home. Now, I am big. 6'2 and about 275 pounds. It would probably take a LOT more than 2 beers to put me anywhere near the limit. About 10 minutes after leaving, I was changing a CD (which was stupid, I know.) I must have gone over the line. Next thing, I saw flashing red lights in my rearview mirror, so I pulled over. The police officer asked for my license and registration, and then asked, "How much have you had to drink tonight?" I told the truth, "Two drinks, the last an hour ago. I'll be happy to perform tests if you want." So he has me step out. He first has me blow into the preliminary breath test. Then he has me perform a couple FSTs (walking in a straight line, counting 1234 4321 on my fingers 5 times) which I did with no problem. Then he said, "Well, you admitted to me you had a couple drinks. I technically can bring you in, even though I probably wouldn't get a DUI on you. I want you to sit by the side of the road for a half hour. It is 9:30. You can proceed at 10. I have youre license number and home address, so if I find out you were on the road before then, I know where to find you." So he drove away and I waited a half hour and left. I am thinking though. I think he was covering his ***. He knew he probably wouldn't get a DUI on me, but was afraid if he said, "OK you're free to go," and I pulled away and had an accident, he could be in trouble. I really don't think he was really serious, because if he really thought I was unfit to drive, he would have sat there for a half hour to make sure I didn't go anywhere, and not driven away and left me alone. If I had driven off and he drove by and saw my car gone, could he really have chased me down in a different state? I was more than a half hour from home, and by the time I got home, I may not even have registered at all on a breath test. Looking back, it didn't seem like he had anything on me. Does this seem like an abuse of power?