Add to this, I've noticed several lawyers think along the lines of not if the issue at hand is right or wrong, but more if they could get away with it in terms of law. E.g. several institutions fight in a legal manner knowing the other person will give up. The big institution with a team of lawyers on retainer can keep this going on indefinitely while the little guy has to fight for every inch.
Trial lawyers often times are in a constant state of mentally fighting. Such a profession may have it's appeal for a young scrappy professional, but long-term it leads to issues such as substance abuse, broken relationships, etc. Getting to the point you work with a lawyer, you do say $15,000 of work for them and they decide not to pay you, don't expect their sense of right and wrong to dictate what's going on. More like, "hey I'm not going to pay the doctor, and I know if he takes legal action against me he knows he'll be spending 10x that much in legal fees and time devoted to suing me that he could've made up seeing patients so he'll give up." And from what I've seen several do give up.
Then add to this it's not like there's an online source for expert witnesses to know who the scumbag lawyers are that won't pay you. I'm being snarky but frank-I've seen online forums for rating providers of various illegal activities (e.g. Joe on 6th street, Internet phone # will get you quality activity, 4 out of 4 stars, with dozens of positive ratings), but no source of information to let me know if the lawyer I'm going to work with is going to pay me.
The only protection other than experience in working with local lawyers is in your contract have a retainer fee (an upfront fee) and a milestone written in where if you do not get paid via increments you will not continue to work. I have that written into my expert-witness contract and you may have to be a pain in the ass with that lawyer where you want the cordial relationship and remind them to pay you or no more work.
My last expert witness case, the defendant had to have all of his monetary transactions approved by a third party because he was inappropriately accused of having dementia, so payments were tied up for several days. Then add to this in the middle of the case he wanted a new lawyer, and I told the new lawyer I wouldn't restart working on the case until I got paid from the prior lawyer who delayed payment likely because of the third party and not due to bad intent.
It was the first time I suspected a lawyer was going to play hardball with paying me, and I did get paid, and it did turn out it was likely because the third party situation with no bad intent on anyone, but for weeks the issue was bugging the heck out of me. I had to make a declaration I was not going to do anymore work until I got paid. Also the new lawyer had to spend a lot of time and effort to figure out what was going on with why it was taking weeks to get me paid from the prior lawyer. I remember saying to myself, "yep it finally happened to me." Well I did get paid, but each case, unless I know the lawyer well, I get the suspicion the guy's going to screw me. Unfortunately I've seen colleagues screwed over with getting paid, and I've worked on several cases where I did get paid, but worked with the lawyer enough to see this lawyer was a total scumbag who was completely into doing anything, even if illegal and unethical so long as no one could prove it and he could get away with it.
One particular case in mind occurred where I was asked to work on the defense for a physician, and after I reviewed the case I told the lawyer there were several strong defenses because the physician he was defending didn't commit the problems in the case, and it was very much glaring the problems were caused by a specific other physician. The lawyer got mad, told me his partner was defending the other physician and that guy was a big money producer for them cause he always gets sued, and that I really screwed up on this cash-cow case cause now he can't work with me. Lawyers aren't supposed to compromise the defense of their client so that their partner's defenses for other clients could better work out, it violates their code of ethics, but here it was happening. Then the lawyer pointed out that in the future, if he works with me, it's better for him to lay out everything I'm supposed to say and I should just say yes and that I would get paid an extra special amount. Seriously this type of below the belt experience I've seen in expert witness work just under half the time.
I also did a rotation while a resident with a forensic psychiatrist who pretty much said anything the lawyer wanted to say even if it was completely inappropriate. Lo and behold while I'm a fellow I see this guy considered a high up guy in AAPL. I remember seeing him testify that if a doctor or nurse was physically assaulted, the patient shouldn't be held accountable even if it was clear that the patient knew what they were doing because "it comes with the territory," and that it would "violate" our professional ethics to seek legal action against the patient. WTF. And no one in my residency seemed to know or care this was how this guy operated. No one at AAPL ever saw this guy testify in person, no they just saw his AAPL articles (that I thought were weak but whatever).