Hold on a minute! I was merely answering the OP's question.
One of the crashes was caused by a defective filter but a relatively LARGE NUMBER of other planes have been found to be suffereing the same problem.
In due course, how many of these other defective planes would have suffered the same fate as the first one? I'd wager the chances were fairly high.
I'd say that constitutes a major design flaw, wouldn't you? If the landing gear had been designed differently then it is very likely landing gear would be near 100% reliable...
Also, it is not clear whether the two planes with corroded bolts had deficient filters or not. It is also not clear whether the faulty filters could contribute to the corrosion or otherwise aggravate the problem.
What is clear is that the landing gear needs investigating and potentially re-designing. It seems that maintenance/inspection procedures should be tightened up too, and documentation re-writing.