Yes but was the zip archive 1.45GB or the file within it? To be more explicit, how big was the .zip file, and how big (uncompressed) was the file within it?
(it's important so when I test it I can test under the same conditions)
I haven't been able to reproduce this in initial testing.
We're wondering if the delay could be caused by your anti-virus software scanning the archive (or the extracted file, or both) - could you try to replicate the issue with AV disabled?