Lindsay Lohan -- Victim of a Setup?

If Lindsay Lohan really did push and shove a woman at The Standard Hotel in West Hollywood last week -- it's news to the people working there, because they never even saw her.

We have spoken with 6 people at the hotel -- some of whom were working on the night in question -- and none of them saw Lindsay that evening. What's more, none of them heard even a whisper that Lindsay was in the hotel, and none heard anything about an altercation.

We broke the story ... a woman claims Lindsay accosted her because she was speaking with a dude Lindsay was scoping out. The woman filed an incident report with the West Hollywood Sheriff's Dept., and detectives are looking into it.