All the cases you have mentioned have been umpiring mistakes, not a failure of the technology aspect.
Again why are you trying to distinguish between Human interpretation errors, and Tech errors. Both are equally a part of DRS. The ump interpreting the data is as much a part of DRS, as the tech which is providing the data for interpretation. So which part is failing is irrelevant. The overall system still fails.
Hawkeye is tried and tested
Umm ... is it? I know the ball tracking part is, in so far as it tracks the path the ball has actually taken.
However the part of DRS, which predicts what the ball would do after impact with the pads, is the part that BCCI has a problem with. BCCI says that if the ball impacts the pads just after pitching, there is no way Hawk Eye can possibly account for the variable bounce if say the ball hit a crack, or a damp spot or the dusty area of the pitch. In all these years on this debate, I have never read one article that says the path predicting part of DRS was ever tested, or tested especially with regard to Cricket. Even if the test was done for tennis, it doesn't hold for cricket, as Tennis is played on a pristine surface. Cricket on the other hand, is played on pitches that are full of uneven spots cracks, dents, and the bounce also varies depending on the pitch or whether the ball is new or old. A ball will bounce more in Aus than it will in India, and how can Hawk Eye, when predicting the path the ball will take, if the impact is just after the ball has bounced, possibly account for all these variations. Has this point ever been tested? If it has been then why doesn't someone send the report to BCCI and say your objections have been proved to be rather pointless.
Also the larger point remains, and its this, even if u are right, that after DRS 95% more correct decisions are now made, which is better than say the previous 94% more correct decisions, before DRS. However the point is that 5% are still wrong, and that is not where I have a problem with DRS, that its not 100%.
The problem with DRS is that in the 5% errors, if there are errors that include those from DRS, and there are (Akmal being the latest) be it tech fail or human interpretation, then the system needs to be looked at. I don't see why ppl are so eager to argue with that.