I suspect this dog has NOT actually been 'fine' and 'good' with previous babies, I suspect they've struggled and have no further tolerance.
I can pretty safely state however that the dog did not 'try to bite' - dogs move far faster than us, if the dog intended to land a bite, the dog would have landed a bite unless there is extra information such as the dog is blind - dogs don't miss.
The significance of that is.. this dog IS still communicating their discomfort without actually biting.
Likely an air snap (often interpreted as 'tried to bite but I pulled them away in time').
That means theres time to improve this!
Separate dog and baby - the dog is NOT comfortable with a crawling baby and tbh, very few dogs are - its scary, babies are unpredictable, grabby, smacky, wobbly, prone to strong smells and loud noises, and they DO NOT respond to the polite dog-language communications to back off, give the dog space, leave me alone (stare, freeze, lip curl, growl, air snap etc).. Instead.. they keep coming, which is rude and confrontational!
So the safest kindest thing you can do for both is - well ideally, don't go round there, but if you must - separate them.
If this were YOUR dog, id recommend you reward the heck out of the dog for moving away from the baby and ensure the baby can never approach the dog or trap them. Dogs often forget they can move away, another misunderstanding - people think 'well if he didn't like it... (being smacked, hit, grabbed, climbed on, approached)... he'd move away'.
It doesn't work like that - worried or anxious dogs (and people do this too!) often freeze and forget that moving away is an option.
If we can encourage moving away and reward it by chucking treats so the dog wants to follow them... away from the baby, great!
I suspect it isn't practical to do this with the dog being someone elses - do you know what they have done in the past, have they rewarded the dog for being gentle around babies/ignoring babies, or have they told the dog off for freezing/lip curling/growling (if they have this will make it worse and tbh that would mean I would NOT let my baby go near the dog again. Punishing communication like that is what results in dogs who 'bite without warning'.)
Whatever you decide to do re their dog, I would make a strong point of distracting your baby from any other dog and rewarding them for that - all too often people make a BIG deal about approaching doggies, touching doggies etc when actually what would be far safer is teaching children 'yes the doggy is nice we can look at him from HERE and NOT go and touch/hug/fuss' until they are old enough to understand how to touch nicely, that a growly face is NOT a smile etc etc.