HTTP Content length less than File byte-size, did it fully download?

Question

Trying to determine if a user actually downloaded an executable file from a website. I examined the pcap and I see that the Content-Length field = 784,536 but the Server->User is 430,380 bytes. This tells me that the user did not fully download the file. I also downloaded the file myself and see that it is 766 KB. Is it possible that the content-length value based on the HTTP header will not be EQUAL TO the file size of that EXE file if it is downloaded (the local file size)? Is this correct?

Packet Capture Data (I can't post screenshots)

GET /ChromasLite211Setup.exe HTTP/1.1
Host: www.technelysium.com.au
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Firefox/17.0
Accept: text/html, application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us
Accept-Enconding: gzip, deflate
Connection: keep-alive
Referrer: http://technelysium.com.au/

HTTP/1.1 200 OK
Date: Thu, 01 Aug 2013 17:28:17 GMT
Server: Apache
Last-Modified: Mon, 15 Apr 2013 08:29:57 GMT
Accept-Ranges: bytes
Content-Length: 784536
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: application/x-msdownload

MZP........................@.............................!..L..This program must be run under Win32


Entire Conversation (430722 bytes)
Users IP -> Server IP (342 bytes)
Server IP -> Users IP (430380)

When I download the file from the site it shows as, "Binary FIle (766 KB)"

Answer 1

Converting Bytes to Kilobytes

784,536/1024 = 766.14

Answer 2

No. The user did not download all the bytes.

If a server sends a Content-Length header, that is exactly how many bytes of content it intends to send as the HTTP Response Body. If less than that number was sent, then something happened (Client terminated connection, Client timed out, etc.)