serious conflicts between python pks installed via yum vs pip

[Neal Becker]

80 wrote:

> 2012/2/10 Neal Becker <ndbecker2 at gmail.com>:
>> I've seen this repeatedly, with often very serious consequences (complete
>> failure of update from f15->f16 for example).
>>
>> Between packages installed via pip, and packages installed via yum, some
>> packages seem to switch between
>>
>> e.g.,
>> numpy-1.6.1-py2.7.egg-info
>>
>> being installed as a file and the same name being installed as a directory.
>> This can cause subsequent rpm update (via cpio) to abort.
>>
>> I don't know what's causing this, but IMO this is a serious problem.
>>
>> --
>> devel mailing list
>> devel at lists.fedoraproject.org
>> https://admin.fedoraproject.org/mailman/listinfo/devel
> 
> Never use pip outside an isolated environment (use virtualenv)
> 
> H.

Really?  This is the only answer?  Can't we tweek rpm/yum to accomodate this?  
Does anyone understand what is causing it?  Why would pip install the egg-info 
differently than rpm?