Egos tend to get inflated and pampered in this law-talking business (although I am quite certain it happens in other professions as well). Given the adversary nature of the law, attorneys tend to butt heads, take things personal, and well, get nasty.
There are certainly times when it is difficult to keep your emotions in check, but is there an advantage to mistreating the other side?
“It gets better results for clients”
Being a hard-nosed and strategic negotiator gets clients better results. Being a jerk gets opposing counsel mad and gets you a bad reputation.
To most people, being mistreated merely entrenches them, it does not cause them to cower, shirk, and give up on a case.
“They started it”
Good for them, but we are adults now. If opposing counsel flies off the handle in an email as part of a discovery dispute, they just created an attachment for your affidavit down the road (assuming it is relevant). If you can keep yourself in check, you look reasonable while the other side? Well, not so much.
There is no reason to stoop to their level if they are really being ridiculous. Frankly, the whole purpose of them acting ridiculous could be an attempt to get you to do something stupid, so don’t do it.
“I had to let them have it”
No, you didn’t. Go for a walk and blow off some steam. Shut down your email before you send a nasty reply. Sure, the instant emotional satisfaction will feel great. Ten minutes later, you will regret it. The next day, you will feel bad you stooped to their level.
Stick to your guns and keep it civil. It will pay off in the long run.