disconnecting or not of battery when spot welding on an exhaust

[scorchy]

So the other day I tack welded  on an exhaust with battery not disconnected. Now the quickshifter dont work. I kept the earth wire onto the tip of the exhaust and tig tacked a part on the busa.
Is this me or did this part just blow, the ecu and rest is still good.
Am I guilty???

 

[the_BOBNOB]

 

[ClemS]

 

[BFG]

 

[Bram]

 

[Smuggy]

 

[MINZI]

 

[oldmannorman]

 

[Airguitar]

 

[Smuggy]

 

[lecap]

 

[volroom]