I don't see any way to fix it as there are generally very few after marker parts for Ruger pistols (well, when you compare them to, say, Glock).
However, keep in mind that I am a lefty when it comes to pistols. The ambi mag release is one of the things I like about my P89. Also, every pistol that I carry has the mag release facing OUT due to this. While I won't say it doesn't ever happen, I have never had the release accidentally depressed enough to loosen a magazine. well, except one time with my LCP, but that has to do with it being in my back pocket. You aren't going to pocket carry a P95
Then again, I have never drawn under pressure. However, I think a good holster could potentially solve that. I make my own holsters (which are hideous but effective), and I generally reinforce the throat just enough to capture the mag release enough that i shouldn't get bumped hard enough to depress it. I dunno if it actually works, but like I said, I've never accidentally dropped a mag.