"A good plan violently executed now is better than a perfect plan executed next week."
- US General George S. Patton
A Classical Arrangement by Vivaldi, just to throw you off...The whine of the imminent attack reminds you of the sound mortars make just before they hit in old trideo movies. Your keenly tuned senses give you half a moment to react, and as a result you scatter like skittles hitting pavement.
Sly runs a few steps toward the front of the store, shouting for security to prepare for incoming- some of the security is even fast enough to begin reacting, turning toward the front of the store and reaching for sidearms.
Galbraith, the 'Tin Man' throws his jacket over Springbok's shoulders, giving her some protection and relieving himself of a burden that made it difficult for him to move. Rastire seems too surprised and terrified to move.
Kinsey mumbles to himself, and as he embraces his inner Zen, he sees the world slow down.
Scarlet readies her weapons, and scans the room.
Ingo drops into full VR, readying his code to slice through this place and any security hacker that might be waiting in the wings.
The resulting explosion doesn't disappoint, and punches a nice hole in the 'impenetrable walls' of the McHughs. There's shards of something, and a concussive blast bounces off of you before continuing into the store, knocking over trays, tables, and other patrons.
The explosion further galvanizes the difference between the sheep and wolves, as patrons dive to the floor in terror and begin screaming. The cute girl against the wall even tries to send out a PAN message to her friends about how scared she is. Rastire, put off balance by the explosion, somehow chooses 'flight' out of her fight or flight options, and tries to run. She's about three big steps away from the table when the drone comes through the hole in the wall, sighting in on her with a spotlight and marking her with a laser target designator. Not being too picky, the machine opens up in a wide burst, turning several tables to kindling and the people seated at them to twitching meat piles. Rastire goes down, curling beneath Galbraith's jacket.

Clearly marked as a Renraku Kitsune-Class drone, this medium sized flying tripod is stability and power, armored and lethal. It opens fire on the area around Springbok, turning the patrons into chunky salsa and shredding Galbraith's jacket. There's almost no chance the little hacker girl survived.
Okay, so I played a dirty trick, and punched a hole in the back of the 'impenetrable security' of McHughs. Sorry for the elaborate setup, I was just trying to give you the information you asked for. Sometimes a chair is just a chair. 
Ingo, does Eric have reality filters on? For reference, that 'mortar' sound was a missile taking out the hardline matrix access, and backup power. This place is dark, and things are not going to go well inside. On the plus side, the security decker should have registered for a HTR team to hit this location the instant someone started jamming the area. That is, if they're not bleeding out of their eyes from Dumpshock.
Everyone resist knockdown, and then we'll start the real initiative order.
“Everybody has a plan until they get punched in the face.”
― Michael Gerard Tyson