I noticed this long ago but finally decided to make the bug report.
Description of the problem, what happened: As title states, any destroyer gets double damage from any shot made by its own pilot, even when no enemies are nearby.
What did you expected to happen: To not receive double dmg from self fire.
The conditions during the situation: Happens any time anywhere. Testing to provide logs was made in OS without station protection, weapons used were halo launcher and tempest launcher T5 mk4, firing them close to a wall in order to get self fire. No enemies, players, nor NPCs were nearby at test time. Ive experienced this in all game modes with different destroyers.
Further details on the issue: I have considered resistances (shield and hull) and explosive dmg modifier on destroyers; here’s the math: tempest mk4 T5 base dmg is 3780, now with explosive modifier for destroyers (x2) dmg raises to 7560 per missile, applying hull resistance (57%) damage drops to 3250,8. However the damage received was around 6780 (as you can see in the screenshots), which is 2,09 times more than 3250,8: the double. Halo launcher mk4 T5 dmg is 5554 with 8 turrets, explosion modifier increases it to 11108, applying resistances (59%) it drops to 4554,28 and 9245,19 with critical dmg (103% bonus), however damage received with hulls was 9257 for normal hits and 18666 with critical hits: the double once again (no photon effect was present). Ive also seen crazy numbers with photon emitter but were not tested this time.
Frequency of occurrence: as stated above: happens everytime everywhere, no exception.
If possible, the time when it happend. In this case we will be able to look more closely to the server logs. Also mention your time zone: no need.
Information on the configuration of your computer (DxDiag): no need.
The results of this [program](< base_url >/index.php?/topic/25324-info-connection-losses-high-ping-and-related-issues/) if the bug report is related to connection issues: no need.
If the complaint is related to Sector Conquest, it is necessary to specify the location and time + timezone of the happening: no need.
Papitas is very near to a structure and receives indirect explosion damage.
This happened to mee with an engineer frigate, also, when I shot missiles in false direction at the rock I was hiding behind 
Try to repeat problem in Open Space, alone, on two different ships. And attach logs and screensots.
If you may, please, repeat it in separate game session.
Ok, it took me a while but here it is: a compressed folder of 2 different game sessions (exclusively to test this matter) including all logs and screenshots. Tested ships were Sirius (session 1) and Invicible (session 2). Weapons and mods used were halo launcher and tempest launcher mk4 (T5 and T3 respectively), plus wormhole.