#1). WEAR SAFETY GLASSES at all times IN THIS SITUATION!... DO IT! ------ Good idea most of the time.
#2). Ever had a "lady finger" firecracker go off in your fingers? Large rifle primers remind me of this when they "let go." I was doing some cases with a Lee base/de priming rod and plastic mallet. Maybe 1 in 10 would "let go." Maybe 20? With safety glasses, no big deal, just obnoxious. I am sure, without safety glasses, you might get "debris" into your eyes, possible, and hurt yourself... Otherwise... Blood poisoning, I doubt it, but I suppose possible. ERGO: What is it worth to you? If you fire the primer, none of this is a consideration. Your call. I would guess, with a press, maybe slightly less likely and same risks...
#3). Even if you get the primer out without it popping? Then what? Probably enough deformed to make reuse unlikely... And even if you get it re seated, you have mangled it enough, what will the reliability be? If this were an early tv episode with your snowed in in the Yukon and desperate to collect another young moose for food... otherwise, fire the things, be done with it and follow ordinary procedures... luck.