It sounds like his radio may have a CTCSS, or P/L tone enabled on his receive.
Secondly, unless you have a GMRS license, your UV-5RA violates 47 C.F.R, Part 95 Subpart B by having a removeable antenna and being able to transmit at more than 500 milliwatts (1/2 watt).
Check out the following URL for details directly from the FCC web page. Click on the Operations tab for specific details.