Looks like there BCU is having some effect. Culling of birds within a 15 mile radius if proved to be a source of danger is reasonable as a last resort.
I don't know what type of bird or what the danger was but I wouldn't condemn it just because it was a Public park.
The numbers you have are all well and good, but, did they break the strikes down into Species, time, weather etc? The whole picture is needed. I don't think you will feel too good if one of the birds you 'Saved' brings down an aeroplane..
I don't like killing birds so it's always last resort. However, safety of the Aeroplane is paramount in my book.