Jett Ult vs Iso Barrier

I was playing Iso and I had my signature ability active, an enemy Jett runs at me, uses her alternate fire on her Ult and kills me through my shield. I managed to replicate this consistently in custom games and I wonder if this is spaghetti code or intentional design?

Not saying it should be changed, but it might be good information to consider for the upcoming iso power budget redistribution.