I wouldn't worry about the laser failing on the LCP. Even if it did, you have to remember what the LCP is intended for...up close and personal. It's not a target pistol.
You won't need the sights when the robber is only four feet away from you and demanding your wallet. We're talking "belly button" range here. And that is where the LCP excels. It's small enough to conceal in your "Speed-os" but, with the right ammunition, is adequate enough to shake someone's day up.
You won't be looking at the laser either . . .