Was this veterinarian correct?

I took my dog into the vet today because the past 2 nights he has been waking up at 2 am puking and having diarrhea. I switched his diet to boiled chicken and rice. He has had a similar issue in the past, but this was over a year ago, and after switching him to a Purino Pro plan food he has been fine (until recently). We tried a variety of different brands, and this was the only one that seemed to agree with him.

Anyways, I took him to the vet today and he saw a vet that was new to the practice. He seemed to think the current issue is related to the issue in the past, and was suggesting an elimination diet, with the possibility of my dog eating only boiled beef and rice for the rest of his life. To me, this seemed a bit odd. There seemed to be a lot of tension between him and the vet techs. For these reasons, and a few other comments he made, I am a bit wary of his advice. He was an older guy who continuously referenced his experience working as a scientist in the lab. I ended up spending $217 for the visit. I'm not sure it was worth the money.

I could be totally wrong, and this may be very good advice. I'm just curious to get other opinions.

My dog is a black lab and heeler mix. He's about 2 years old and is neutered.

Thanks in advance!