Well, pagers are not military products. And second, except for ordnance, you don't need any license to manufacture any product.

For products that can have dual-use capabilities, you need an export license that is given per customer (at least in the EU) where some due diligence is performed. If the company is a reseller in Lebanon and there are no export bans for that country, they can be sold/bought without an issue.

The fact that somewhere in transit they were modified, the manufacturer or seller cannot be held liable for it.