Hello Oussama
Indeed you are correct. I actually went into Wireshark and verified this as well. I see that an EIGRP neighbor will advertise a route learned from its neighbor back out of the same interface, but with a scaled delay value of 4,294,967,295, which is indeed infinity. Take a look at this wireshark output:
This is an update message sent from R2 to R1, where R1 has already advertised the 1.1.1.0/24 network to R2. So here R2 is re-advertising this destination back to R1, but with a Scaled Delay of infinity.
Now according to the RFC on EIGRP, this behavior above is poison reverse. Split horizon is considered a different rule. Both achieve similar results, but they are distinct from each other. Specifically, it says:
In EIGRP, split horizon suppresses a QUERY, where as poison reverse advertises a destination as unreachable.
How each one is used and when are more clearly stated in the 5.4.2. Split Horizon and Poison Reverse section of RFC 7868.
I hope this has been helpful!
Laz