Non-Public UK Gov IPs in my US Firewall Logs

[LinuxTracker]

I think this is a general Internet question.

Setup:
I recently started blocking IPs in the 25.0.0.0/8 range and specified that those packets be logged.
Next - pfSense firewall logs show blocked connection attempts to/from several addys in 25.0.0.0/8.
The ports indicate it's uTorrent traffic.

Here's the thing:
25/8 is assigned to UK Ministry of Defense and is not publicly routed.
It's also used as an internal address block by Optimum WiFi, Hamachi VPN and others.

uTorrent may be confused and that could explain why traffic to 25/8 shows up LAN-side.

But - I don't get how traffic originating from a 25/8 IP could possibly show up on the WAN side of my firewall.
25/8 isn't used by my ISP and my WAN is connected to a dumb-bridge.

What am I missing?
I realize this isn't very important but it's bugging me - so thank you for reading this.

ref:
Here's the relevant rule.

[johnpoz]

And what did it block?  Was it broadcast traffic?

[cmb]

Whether or not something should be found on the Internet doesn't necessarily matter. Bogon or assigned but unrouted IP space is hijacked and announced by those with nefarious intent all the time. Alternatively it could be something your ISP is assigning internally and NATing, could be that there were routes for 25./8 in the Internet routing table at some point in time (there isn't right now, at least not on our full BGP feed). It also could be any number of other things depending on specifics.