I think that is extraordinarily unlikely:
A) If that were the case, and Reynard did have -100% SRD, he wouldn't have to wait for "half a second" because he wouldn't have any delay. His shields would always be recharging. The fact is that there does exist some delay, and I suspect that Reynard is under-reporting the actual amount of time it takes his shields to start recharging.
B) I tested a 4.2 second Bee with 10/5 Ward and -7.2% from Badass points, and there's no way it started recharging in the .53 seconds suggested by that math unless there's some hidden "hard" delay cap that somehow exists despite a complete lack of supporting evidence.
C) All negative-signed modifiers in Borderlands 1 were handled via the reciprocal method wherein a "100% reduction" was actually a "100% increase in rate" AFAIK.
D) Other negative modifiers don't work like that now. -100% Accuracy halves your accuracy, it doesn't increase your spread to literally screen-wide proportions.