Can the following situation be termed as "Possession of a forged instrument?"

The paperwork required in working for a gov agency is monumental. I was working 4 months, unable to contact the doctor I needed for signature to get paid. I changed the date on a form and gave it along with other papers to my submitter.She did not check with me and sent the papers in. I called my supervisor to let her know I had decided to wait until I got the correct signature and she said she would disregard the paper she received. We had a falling out and AFTER the correct signature was obtained and a meeting took place to discuss a health plan for the patient, she decided to use it against me and said I forged a document. If she knew about it and decided to ignore it, isn't she complicit in the wrong she is making out of this?