Anyway, there's holy laughter movements, then there is holy laughter. Yes it can and does happen at times. The word drunk does not always imply alcohol. It can mean overcome with extreme emotions. Using it to describe the experience is entirely valid. You can be drunk with love, drunk with envy, drunk with rage ,etc. Drunk in the Spirit is valid.
The manifestation of tongues must have been more than just simple slurred speech. The tongues sounds like a foreign language. And no one who hears another speak a foreign language says "they must be drunk". I can tell when a person speaks german, french,, or chinese, and I'd never say they are drunk. But if they are staggering around with maybe fits of laughter or emotion or appear to be out of themselves, only then would I say they are drunk.
The OT says that when the Spirit comes upon them they will be a different person.