Pset6 server - 501 Not Implemented error

Question

This is related to my earlier question, but as it turns out that I mistyped the error code in server.c and actually have a 501 Not Implemented error (instead of a 505), I made a new question because the answer was good but I still have an issue.

Whenever I try to load cat.html I get the 501 error now. According to the spec (http://cdn.cs50.net/2015/x/psets/6/pset6/pset6.html#validate_request_line), there are two things that should trigger this:

1. If absolute-path doesn't contain . (therefore a file extension)
2. If request-target doesn't begin with /

This is my condition for #1

        if (strstr(line, ".") == NULL)
        {
            error(501);
            continue;
        }

And this is my condition for #2

     else if (requestLine[REQUEST_TARGET][0] != '/')
        { // not implemented
            error(501);
            continue;
        }

Someone on slack also suggested an alternate method, which confuses me because it doesn't seem to check either condition for 501 mentioned in the spec (not having "GET" is supposed to be 405 Method Not Allowed)

char buffer[4];
strncpy(buffer, line, 4);
buffer[3] = 0;
char* method = "GET";



        //if 
        if (strncmp(line, method, 3) != 0)
        {
            error(501);
            continue;
        }

I've already checked my lookup function and it should be getting the proper file extension, which is the other condition that should bring up a 501 error.