However at the same time a lot of them claim to be critical of US govt's policies on war, drones, extra-judicial killings and so on. All that taken into account is surprising that they as a group would rush to discredit Iranians' capability and ridicule this situation.

It is interesting that they are essentially playing along to the US govt. propaganda. The govt. knew what had happened but lied, telling the media a malfunction occurred, and the drone 'drifted' randomly into Iranian territory. I expected them to lie and make shit up. That's fine. But is is interesting that groups liberals are also doing that, without being coerced or forced to do so. It illustrates an interesting process that happens were supposedly fairly liberal individuals still end up White House lapdogs without even realizing it.

It is also funny how after more evidence comes out, neither the media, nor say, Redditors, go back and admit their previous mistake, instead the strategy moves to "ridicule".