thank you so much guys that is really helpful and puts my mind at rest.
i decided to have a closer look at the snake in the egg to see if there was any obvious issues, such as a lack of egg tooth.
although from looking through the slit in the egg it looked to be viable, it most definitely was not. the lower body of the snake was extremely kinked and the snake also looked to have a cleft lip. i could not see any of this through cutting the egg as only the neck and upper body was visible.
it’s sad but is also the circle of life, some survive and some don’t. it’s just a relief that it was unlikely to be human error, so thank you all for replying