Hello David I'm sure that has happened since the invention of the Bic lighter.
When you want to make a spark using steel on steel it never happens

I know of someone who was burned by looking at a 76mm gun recoil system in a Cougar. He didn't wait for a flashlight and used a Bic lighter to see where the hydraulic leak/spray was coming from.
I believe anyone who's worked enough on firearms has had a mishap regardless of how safe.
If you're not 100% sure you can unload a firearm there is no shame in asking someone who can.
I almost became too impatient firing off a small cannon, the fuze burned but no bang. As I approached many seconds later the "bang" did happen. Luckily I was not behind it as it recoils a few feet and has good weight to it.