Hm, we haven't heard any reports of Chrome specifically causing issues that I'm aware of (some of us here use Chrome as our default browser). What we probably need to do is look for any consistencies in the problems. If you have a unique identifier for each person and know who was having issues, you can look in their data record for things like what operating system and browser agent string they have. Or perhaps the problems happened at a specific period of time and you can look into the server to see if a lot of people were taking it at the same time, etc.
If we are hosting the survey for you on our hosting system, you can send an e-mail to hosting at sawtoothsoftware.com and they should be able to check on some things like uptime and server logs, etc.