"tā gāoxìng de tiào qǐlái" distinguishing 得 vs 地 If you hear, "tā gāoxìng de tiào qǐlái," there are two interpretations:


他高兴地跳起来。 He jumped up happily.
他高兴得跳起来。 He was so happy that he jumped up.


Or another example: tā shūfu de shuìjiào.


他舒服得睡觉。 He is comfortable enough to sleep.
他舒服地睡觉。 He slept comfortably.


Are these actually ambiguous when spoken, or are there other rules or clues that help determine the meaning?

Do native speakers use 得/地 carefully in situations like this when writing?
You won't hear any difference in spoken because both are pronounced the same de. 

In writing, 他高兴得跳起来 is correct.  他舒服地睡觉 and 他舒服得睡觉 are not idiomatic because they are  not a typical Chinese way but English.  We'd say 他睡得很舒服 in this case.