My question involves a traffic ticket from the state of: Massachusetts

I'm coming down the ramp, and there's a car coming along in the right lane. Still in the incoming lane, I accelerated up to 65 mph (The limit) to merge, with what should have been plenty of room. I didn't notice that the car coming up the highway had closed quickly into my blind spot, (above the limit) and I pulled in front of them. No real risk of an impact, but it was relatively close.

It turns out that the vehicle is Mass State Police, and I see the a wall of blue lights. (Figures) I pull over, and he continues past and pulls over the next car up ahead of us. He pulls over that car and I continue on. About a mile to a mile and a half down the road, over the next hill and out of site of the last time I saw him with that other car pulled over, I see a car flying up the highway behind me.

Long story short, he's angry, and I get cited for failure to yield because he was "on the main line" and "had to hit his brakes".

The point that I'm getting stuck on is, he was exceeding the speed limit, without his warning lights on, in order to catch up to another car he was pulling over. If he'd been at the speed limit, or close to, I would have been able to merge with no trouble whatsoever. Also, the highway was essentially empty besides him, myself, and the car he was going after, which would have given him plenty of room to move into the left lane to allow me to merge safely.

So, the question: (Sorry for the long story). Was this citation justified?

Thanks in advance.