I know this ain't right, but did I break it?

My sister has an 04 CR-V that lunched its starter.  I pulled it off, my Dad knew a guy at the rebuild shop, and he went and traded it in on one that had already been rebuilt.  Fine.  He says that the guy tested it before he sent it out the door, but I wasn't there.

Initially I was going to test the new one to make sure it worked, but I didn't feel like going out in the cold to get my cables or jump box.  And this guy has been rebuilding starters and alternators for decades so I figured I didn't really need to.  I got it all back together last night and as soon as I touched the negative battery cable to the post, the starter started spinning.  I pulled the ignition wire off the starter and tried again.  No change.

So, I went ahead and took the intake manifold off again (well, the upper plenum anyway) and pulled the starter.  Again.  Put it on the floor, hooked up the jump box to the case and the battery cable terminal.  Switch the box on and the starter just takes off.  It doesn't appear to snap the gear forward, it just spins. 

The starter looks roughly like this one:

As far as I have ever encountered, the only real way to screw up the install would be to tighten the nut that holds the positive cable so much that the copper stud breaks off.  I got the nut snug, but I didn't use a torque wrench on it. 

I was going to see if maybe the solenoid was stuck or something by trying to put a jumper wire on the ignition switch connection there and/or try to manually push the gear back and forth to see if it's just a little stuck between.

Assuming neither of those things does it, is there some way I could have screwed that up and caused it to fail in this manner?  Or is this just an oops on the rebuild?

The good news is that I can get the intake manifold off and the the starter pulled in about 30 minutes now.  So I've got that going for me!

Apart from physically breaking something off I don't think there's any way to damage the starter.

That is a potential failure mode for freshly rebuilt starters.  Not sure what happens in there to cause it, but have seen it twice in parts store remans.

Internal short in the solenoid could cause the Battery positive terminal and the starter motor terminal to connect and the starter to hang like that but .... or a short between the Battery positive and the terminal from the ignition switch, but ... I have seen it several times but usually on starters with a hung solenoid.

I have had this on rebuilds. Yes new ones are expensive but I have never had a new starter be bad out of the box.  

I appreciate the sanity check!  I didn't think there was any way to really screw that up but it's a little different when you're sending back a part and have to look the guy in the eyes who actually worked on it.  If I was just running this thing back to the counter at the parts store, I wouldn't really think twice about it or be that surprised to have a dud.