Differences in specific free radical reactions enthalpies


> 
> Iodination of alkanes using iodine $(\ce{I2})$ is usually an unfavorable reaction. Tetraiodomethane $(\ce{CI4})$ can be used as the iodine source for iodination, in the presence of a free-radical initiator such as hydrogen peroxide. Propose a mechanism (involving mildly exothermic propagation steps) for the following proposed reaction. Calculate the value of $\Delta H$ for each of the steps in your proposed mechanism ($\ce{cp = cyclopentyl}$).
>  $$\ce{cp-H + CI4 ->[H2O2, heat] cp-I + HCI3}$$
> 
> 
> The following bond dissociation enthalpies may be helpful:
>  \begin{array}{lr}\hline
> \text{bond} & \Delta H / \pu{kJ mol-1}\\\hline
> \ce{I3C-I} & 188 \\
> \ce{HO-OH} & 213 \\
> \ce{HO-I} & 234 \\
> \ce{cp-H} & 397 \\
> \ce{I3C-H} & 418 \\
> \ce{cp-I} & 222 \\\hline
> \end{array}
> 
> 
> 


From the book: L. G. Wade *Organic Chemistry*; 8th edition; Pearson: 2013; exercise 4-57. 


The correct answer is given as:
\begin{align}
\text{Initiation:}\\\hline
\ce{HOOH &-> 2HO\*}& \Delta H &= \pu{+213 kJ/mol}\\
\ce{HO\* + I-CI3 &-> IOH + CI3}& \Delta H &= \pu{-46 kJ/mol}\\[2ex]\hline
\text{Propagation:}\\\hline
\ce{cp-H + \*CI3 &-> cp\* + H-CI3}& \Delta H &= \pu{-21 kJ/mol}\\
\ce{cp\* + I-CI3 &-> cp-I + \*CI3}& \Delta H &= \pu{-34 kJ/mol}\\\hline
\end{align}


The overall enthalpy is $\Delta H = \pu{-55 kJ/mol}$ for the propagation steps. 


In the book, there is also an overall table of bond dissociation enthalpies.
One important one I used here is the one of water, $\pu{498 kJ mol-1}$.


I have a significantly more exothermic process here:
\begin{align}
\text{Initiation:}\\\hline
\ce{HOOH &-> 2HO\*}& \Delta H &= \pu{+213 kJ/mol}\\
\ce{cp-H + OH\* &-> cp\* + H2O} & \Delta H &= \pu{-101 kJ/mol}\\[2ex]\hline
\text{Propagation:}\\\hline
\ce{cp\* + I3C-I &-> cp-I + I3C\*}& \Delta H &= \pu{-135 kJ/mol}\\
\ce{I3C\* + cp-H &-> cp\* + I3C-H}& \Delta H &= \pu{-21 kJ/mol}\\\hline
\end{align}


Here the initiation is less endothermic, and the propagation is significantly more exothermic. So why is this not given as the correct answer? Am I missing something here? I'm quite new at organic chemistry, so I think I must be wrong, not the textbook.


