^ Yup. Again, in many cases, the use of today's most popular handgun-WMLs means a holster design that's somewhat compromised where it comes to the potential of something - be it an object or a finger - being able to interact with the trigger while the gun is still secured in the holster. With the light physically being wider than the frame of the gun, there's some geometric issues.....
^ The above is from Reddit member
FlyingDog14, and left-to-right are as-quoted verbatim "Glock 20/Safariland 6285, Sig M17/Safariland 7390, Glock 19/old school Bravo Concealment." I could show the same, with my XDms with either the old Insight M6/M3(x) or Surefire X300, with my old Safariland 5188 bucket, RCS Phantom Light Bearing, or my Glock 32/X300, with my Dark Star Gear. My current EDC IWB from KT Mech? Not so much, but that's because the gun is paired with a small and slim Surefire XC1, a holster and light combo which would be unsuitable for open-carry in a duty/service context.....
Also one has to keep in-mind that the interaction does not have to be intentional/purposeful. That someone's finger, be it a child's or a slim adult's (or even the pinky of a rather larger adult that was forced into that opening due to the two individuals' physical, entangled fight) many just slip/pop in there (in the OP's cited case, because the suspect was literally attempting a gun-grab...who knows what the physical forces involved in trying to keep that grab from being successful may have inadvertently produced?) and literally be dislocated, fractured, or even de-ring'ed on the way out has little to do with the simple fact that said appendage caused the unintentional discharge.
These aren't fly-by-night, third-job-to-support-a-case-a-day-of-beer-plus-child-support kydex benders.
Is it dangerous? I don't know: maybe the designs can be further refined (and they have:
and if it is the case that the Department failed to keep pace with modernizing equipment, a case can definitely be made, there) to reduce this risk, but a not-insignificant portion of this also has to do with the light's design. Sadly, in several cases, the lights with the better form-factor falls behind in other areas that are arguably just as important (output, reliability, and durability).
Regardless, as
@KASHIRA-3 noted above, the weapons-retention techniques -as well as simple administrative procedures- which allowed this incident to happen are really what is at the crux of this issue, and needs to be addressed in addition to reviewing the holster/gun/light combo for possible excessive vulnerabilities, on a technical basis.