It's not really an issue since it's only a minute reduction in light gathering power and the active optics was able to correct the mirror deformation after re-calibration.
Speaking of telescope being shot with a gun.. There is a telescope in Texas (Harlan J. Smith Telescope at McDonald observatory) that was shot a few times by someone in the 1970s in the hopes of shattering the main mirror. The overall effect however was only a 1% reduction in the light gathering power and the telescope is still in regular use today. You can find a picture of the primary mirror here [1].
Speaking of telescope being shot with a gun.. There is a telescope in Texas (Harlan J. Smith Telescope at McDonald observatory) that was shot a few times by someone in the 1970s in the hopes of shattering the main mirror. The overall effect however was only a 1% reduction in the light gathering power and the telescope is still in regular use today. You can find a picture of the primary mirror here [1].
[1] https://astroanecdotes.com/2015/03/26/the-mcdonald-gun-shoot...