There may be some low-level stand-alone utilities like partition imaging programs or data recovery software that could have problems, either because they lack the proper drivers to access the RAID set or because they don't recognize the on-disk structure of the data.
But as sub mesa said, any software that you run inside the operating system doesn't know and doesn't care whether the disks are using RAID, no matter what level (0, 1, 5, etc.) it is.
Software only knows about operating system API's and have no direct access to the raw disk contents. In other words, normal applications can never even know they are on a RAID volume, so your IT-guy statement is pretty weak as it is. There's no reason to think running a RAID0 will get you into problems with applications who have trouble with this in some way; it shouldn't.
------------------------------...man will occasionally stumble over the truth, but usually manages to pick himself up, walk over or around it, and carry on.
Reply to sub mesa
There may be some low-level stand-alone utilities like partition imaging programs or data recovery software that could have problems, either because they lack the proper drivers to access the RAID set or because they don't recognize the on-disk structure of the data.
But as sub mesa said, any software that you run inside the operating system doesn't know and doesn't care whether the disks are using RAID, no matter what level (0, 1, 5, etc.) it is.