Well I'll be damned it could be all 4 bulbs are faulty ?..
Let me be more specific ,when I hard brake its at the point where I stop completely and the car jerks slightly that the LEDs turn off and back on quickly.

Loose connection?

Its happend 3 times so far

I installed all 4 bulbs snuggly and securely the probability of all 4 doing that seems so unlikely :(

Do the AT's have the "idle dip" issue? If so, maybe when your car finally stops, the RPM's drop really low for a split second just before true idle really starts and that's when the LED's go out for a second.
Next time you're in the car and brake hard, watch how low the RPM's go and report back.

You certainly can and it's certainly funny!

I noticed this as well under hard braking. AT also. I think it does have something to do with the RPMs dropping suddenly, as the transmission lets the RPMs drop to just before stalling. When I stop gradually, this isn't an issue.

It can still let the revs drop too low... I would bet A LOT that this is 100% tied to rpm dropping too low and voltages dropping.

My BRZ does this with the DRL strips, near as I can tell by playing with it, it's RPM related and nothing to worry about.

LEDs unlike traditional filament bulbs are either on or off, and require a minimum voltage to operate. Assuming you're in gear the entire time you're stopping, the revs are dipping below normal idle and as a result the voltage going to the lights is dropping.

Filament lights would just dim in this situation, but LED lights, if the voltage gets too low, will simply shut off. This is perfectly normal and unavoidable.

Funny i thaught i was crazy, i have swp limited brz and i notice the same thing when hard breaking happens and to confirm this i even tried it again while holding down the ee-brake handle just to rule it out, i dont know about you but i have a canadian spec car, and people talking about rpm, it has nothing to do with it by the time i let go of the brakes im eather not less then 2000rpm or i hvae downshifted to make sure i dont drop that low (i have a manual btw)

You replaced your high beam with LEDs. The high beam when on DRL mode use a reduced voltage so you don't blind people when it's not totally sunny, they're not getting 12-14 volts when in operation.

So maybe you're getting 6 volts or so, any reduced voltage might be enough to shut off the LEDs.

I beleive where talking about the brz witch comes with led drl from factory (right above the fogs) well at least i am!