Looks like you are shorting to the frame or judging by the soldering you might have a short by bridging. In the first picture it looks like the solder is touching the nut. Also you need to know and remember that carbon fiber is conductive, looks like the bare ESCs are against the carbon fiber frame.
Did the wires get hot on the battery leads? It happens fast and could cause the lead to catch fire if it corrodes and gets stiff.
Do you have some flux? I would create seperation between the ESC, PDB and flight controller from the frame, check all solder joints for bridging and then do a damage assessment on all electronics to see if anything looks burnt. After that if you have a multimeter I'd make sure you don't have continuity between the positive and negative. After all of that is done you are ready to apply power and see if anything was actually damaged.
If nothing was damaged then awesome, if that is not the case then you need to determine what all was damaged then make sure that it was that component and replace it.
As for the soldering do you have any flux? If so I'd apply a little and reheat your solder joints that aren't smooth or shiny before flying it. If you don't have any then you could pickup a cheap flux pen or a ruby flux tin. The tins are not specifically for electronics, but they work really well and go a long way, mine usually outlast my 5ib roll of solder, just have to remember to use so little that you can barely see it because that is all it takes.