Re: Statute of limitations
It depends on what you mean by "allows."
1. You could mean the registered mark owner has acquienced in someone's unauthorized use of the mark. A defendant could use this as a defense to an infringement suit. The defense is called laches, estoppel, and/or acquiescence. See 15 USC 1115(9).
2. Abandonment is also a defense to an infringement suit, but it does not necessarily involve acquiescence to another's use of the mark. With this defense, the defendant challenges the trademark owner's rights by arguing that the registrant itself has discontinued use of the mark. See 15 USC 1115(2).
3. If by "allows" you meant the mark owner gave permission for the other use, then the other attorney is right. One may grant and withdraw permission for another to use their mark at any time.
You shouldn't assume that a mark owner has abandoned his or her rights to relief. As stated above, there are defenses to an infringement suit. But, nothing precludes the mark owner from filing suit.
You should have an intellectual property attorney review all the facts of your case and advise you of you rights, responsibilites, options, and possible defenses.
Good luck to you.