What did she mean? :)

Hello, Everybody! 

I'm not native-english speaker, I'm russian. I think my English is not well now, but I hope it will improve:) So, I was surprised when I saw one sentence in this post in present perfect... She wrote: "Last Tuesday I have seen a film on TV...". Hm, I thought if we say about something was happened IN THE PAST (last Tuesday in it) we must use past simple and "Last Tuesday I saw...." is right form. Am I wrong or not? As I understund she is native English speaker ( american ) so it very strange for me... Please, explaine me where I'm wrong and correct my mistakes in this post if you can.

Thank you very much.

Hello, everybody!

I'm not a native (no hyphen) English speaker; I'm Russian. I think my English is not good now, but I hope it will improve. :) ("So" seems strange to start this sentence)I was surprised when I saw one sentence in this post in present perfect. She wrote: "Last Tuesday I have seen a film on TV..." Hm, I thought if we talked about something that happened in the past, we would have to use the simple past, and "Last Tuesday I saw..." would be the right form. Am I wrong or not? As I understand, she is a native English speaker (American) so it seems very strange to me. Please, explain to me whether I'm wrong, and correct my mistakes in this post if you can.