[tor-relays] Relays spamming my OR port

[Logforme]

I run the relay 8F6A78B1EA917F2BF221E87D14361C050A70CCC3

I have tried to mitigate the current DoS by implemented connection 
limits in my iptables using Toralf's template: More than 25 connection 
during 10 mins and you end up on my naughty list.
Lots of connection attempts from the naughty list dropped but still my 
relay gets "overloaded"

However, I have noticed that a few relays also end up on the naughty 
list, and I wonder how that can happen. My understanding is that a relay 
will only open 1 connection to another relay so should therefore never 
end up on the list. Correct?

D767979FE4C99D310A46EC49037E9FE7E3F64E9D is a particularly frequent 
naughty boy.
Maybe these relays disconnect and reconnect to my relay frequently due 
to network issues (effect from the DoS?) or from not having enough 
connections available on the router?

I guess my real question is if these connections are legit and I'm 
hurting the Tor network by using connection limits?