Looks like the laser light was just grazing some edge there, wonder how you fixed that
I'm going to guess he made a 'flash hider' or pin hole. I have used the cheap vape tank tips as flash hiders on my DTR 22mm heatsinks. I opened up the focusing cap hole and glued on the tip to it. Works well and only looks slightly ghetto. Actually those heatsinks are completely ghetto. They have round finned aluminum heatsinks thermal epoxied to them too. But it works.