fuel filter leaking question

[240sxspeedracer1]

Tonight, I changed my fuel filter in half dark, half light. I put in the 300zx fuel filter. I started driving and found out I was leaking fuel. I was wondering, could the fuel filter leak out fuel if the filter is in the wrong direction. The 300zx purolator has an arrow on it that says "flow". I had the flow arrow facing down. Is that the wrong way? Anyhow, I took it out, and flipped it the other way, and then it was fine. But the direction could still be wrong, and maybe the second time I got the hoses in flush. That's another question, if the hoses are not flushly in, coudl that cause fuel to leak out? Maybe the first time, it was so dark that I didnt realize the hoses were in all the way.

So basically, thanks for reading and please tell me if either direction matters and could cause fuel to leak, or is it because the hoses were not flush in and that would cause fuel to leak. Thanks in advance.