Not a great solution - if the user is editing a record and hits cancel after uploading a new file, the old file will already be overwritten. At minimum you would want to save every file with a unique ID rather than using the the product ID to avoid the issue - and then the product record would need to store the file ID. With either solution you end up with orphaned files. And the problem with cleaning up these orphans is that at any given moment you don't know which ones are true orphans, and which ones are about to be associated with a record as part of an active edit/save. And it also just seems messy to have to deal with cleanup at all.
Could someone please enlighten me as to why the HTML5 file type input can not be supported like the other standard inputs in a KendoUI ajax grid?