Me no think a bird strike.
I had a "swallow strike" about 20 years ago and there was blood everywhere. I was amazed how, perceivably, much blood this little creature can have.
In this case probably fatigue, since they are designed to stay intact even for bird strikes.
Different conditions of the strike significantly affect the debris trail.
Directly head-on (direction of flight not the birds head) into metal go splat and the debris radiates outward in a starburst pattern, some trails visible in white light while others are more clearly visible in UV light.
When hitting a domed surface the structure will trampoline under the impact and if it splits most of the debris will squirt inside (ugh). As the dome bounces back outward the bird trail will be trampolined off the structure as a spray. Still visible though in UV light.
Also the front dome on an aircraft is not necessarily designed for strikes by either hail or birds.